loopback-connector/lib/sql.js

1354 lines
39 KiB
JavaScript

var util = require('util');
var async = require('async');
var assert = require('assert');
var Connector = require('./connector');
var debug = require('debug')('loopback:connector:sql');
var ParameterizedSQL = require('./parameterized-sql');
var Transaction = require('./transaction');
module.exports = SQLConnector;
/**
* Base class for connectors that connect to relational databases using SQL
* @class
*/
function SQLConnector() {
// Call the super constructor
Connector.apply(this, [].slice.call(arguments));
}
// Inherit from the base Connector
util.inherits(SQLConnector, Connector);
// Export ParameterizedSQL
SQLConnector.ParameterizedSQL = ParameterizedSQL;
// The generic placeholder
var PLACEHOLDER = SQLConnector.PLACEHOLDER = ParameterizedSQL.PLACEHOLDER;
SQLConnector.Transaction = Transaction;
/**
* Set the relational property to indicate the backend is a relational DB
* @type {boolean}
*/
SQLConnector.prototype.relational = true;
/**
* Invoke a prototype method on the super class
* @param {String} methodName Method name
*/
SQLConnector.prototype.invokeSuper = function(methodName) {
var args = [].slice.call(arguments, 1);
var superMethod = this.constructor.super_.prototype[methodName];
return superMethod.apply(this, args);
};
/**
* Get types associated with the connector
* Returns {String[]} The types for the connector
*/
SQLConnector.prototype.getTypes = function() {
return ['db', 'rdbms', 'sql'];
};
/**
* Get the default data type for ID
* @param prop Property definition
* Returns {Function}
*/
SQLConnector.prototype.getDefaultIdType = function(prop) {
return Number;
};
/**
* Get the default database schema name
* @returns {string} The default schema name, such as 'public' or 'dbo'
*/
SQLConnector.prototype.getDefaultSchemaName = function() {
return '';
};
/**
* Get the database schema name for the given model. The schema name can be
* customized at model settings or connector configuration level as `schema` or
* `schemaName`. For example,
*
* ```json
* "Customer": {
* "name": "Customer",
* "mysql": {
* "schema": "MYDB",
* "table": "CUSTOMER"
* }
* }
* ```
*
* @param {String} model The model name
* @returns {String} The database schema name
*/
SQLConnector.prototype.schema = function(model) {
// Check if there is a 'schema' property for connector
var dbMeta = this.getConnectorSpecificSettings(model);
var schemaName = (dbMeta && (dbMeta.schema || dbMeta.schemaName)) ||
(this.settings.schema || this.settings.schemaName) ||
this.getDefaultSchemaName();
return schemaName;
};
/**
* Get the table name for the given model. The table name can be customized
* at model settings as `table` or `tableName`. For example,
*
* ```json
* "Customer": {
* "name": "Customer",
* "mysql": {
* "table": "CUSTOMER"
* }
* }
* ```
*
* Returns the table name (String).
* @param {String} model The model name
*/
SQLConnector.prototype.table = function(model) {
var dbMeta = this.getConnectorSpecificSettings(model);
var tableName;
if (dbMeta) {
tableName = dbMeta.table || dbMeta.tableName;
if (tableName) {
// Explicit table name, return as-is
return tableName;
}
}
tableName = model;
if (typeof this.dbName === 'function') {
tableName = this.dbName(tableName);
}
return tableName;
};
/**
* Get the column name for the given model property. The column name can be
* customized at the model property definition level as `column` or
* `columnName`. For example,
*
* ```json
* "name": {
* "type": "string",
* "mysql": {
* "column": "NAME"
* }
* }
* ```
*
* @param {String} model The model name
* @param {String} property The property name
* @returns {String} The column name
*/
SQLConnector.prototype.column = function(model, property) {
var prop = this.getPropertyDefinition(model, property);
var columnName;
if (prop && prop[this.name]) {
columnName = prop[this.name].column || prop[this.name].columnName;
if (columnName) {
// Explicit column name, return as-is
return columnName;
}
}
columnName = property;
if (typeof this.dbName === 'function') {
columnName = this.dbName(columnName);
}
return columnName;
};
/**
* Get the column metadata for the given model property
* @param {String} model The model name
* @param {String} property The property name
* @returns {Object} The column metadata
*/
SQLConnector.prototype.columnMetadata = function(model, property) {
return this.getDataSource(model).columnMetadata(model, property);
};
/**
* Get the corresponding property name for the given column name
* @param {String} model The model name
* @param {String} column The column name
* @returns {String} The property name for a given column
*/
SQLConnector.prototype.propertyName = function(model, column) {
var props = this.getModelDefinition(model).properties;
for (var p in props) {
if (this.column(model, p) === column) {
return p;
}
}
return null;
};
/**
* Get the id column name
* @param {String} model The model name
* @returns {String} The id column name
*/
SQLConnector.prototype.idColumn = function(model) {
var name = this.getDataSource(model).idColumnName(model);
var dbName = this.dbName;
if (typeof dbName === 'function') {
name = dbName(name);
}
return name;
};
/**
* Get the escaped id column name
* @param {String} model The model name
* @returns {String} the escaped id column name
*/
SQLConnector.prototype.idColumnEscaped = function(model) {
return this.escapeName(this.idColumn(model));
};
/**
* Get the escaped table name
* @param {String} model The model name
* @returns {String} the escaped table name
*/
SQLConnector.prototype.tableEscaped = function(model) {
return this.escapeName(this.table(model));
};
/**
* Get the escaped column name for a given model property
* @param {String} model The model name
* @param {String} property The property name
* @returns {String} The escaped column name
*/
SQLConnector.prototype.columnEscaped = function(model, property) {
return this.escapeName(this.column(model, property));
};
/*!
* Check if id value is set
* @param idValue
* @param cb
* @param returningNull
* @returns {boolean}
*/
function isIdValuePresent(idValue, cb, returningNull) {
try {
assert(idValue !== null && idValue !== undefined, 'id value is required');
return true;
} catch (err) {
process.nextTick(function() {
if (cb) cb(returningNull ? null : err);
});
return false;
}
}
/**
* Convert the id value to the form required by database column
* @param {String} model The model name
* @param {*} idValue The id property value
* @returns {*} The escaped id column value
*/
SQLConnector.prototype.idColumnValue = function(model, idValue) {
var idProp = this.getDataSource(model).idProperty(model);
if (typeof this.toColumnValue === 'function') {
return this.toColumnValue(idProp, idValue);
} else {
return idValue;
}
};
/**
* Replace `?` with connector specific placeholders. For example,
*
* ```
* {sql: 'SELECT * FROM CUSTOMER WHERE NAME=?', params: ['John']}
* ==>
* {sql: 'SELECT * FROM CUSTOMER WHERE NAME=:1', params: ['John']}
* ```
* *LIMITATION*: We don't handle the ? inside escaped values, for example,
* `SELECT * FROM CUSTOMER WHERE NAME='J?hn'` will not be parameterized
* correctly.
*
* @param {ParameterizedSQL|Object} ps Parameterized SQL
* @returns {ParameterizedSQL} Parameterized SQL with the connector specific
* placeholders
*/
SQLConnector.prototype.parameterize = function(ps) {
ps = new ParameterizedSQL(ps);
// The value is parameterized, for example
// {sql: 'to_point(?,?)', values: [1, 2]}
var parts = ps.sql.split(PLACEHOLDER);
var clause = [];
for (var j = 0, m = parts.length; j < m; j++) {
// Replace ? with the keyed placeholder, such as :5
clause.push(parts[j]);
if (j !== parts.length - 1) {
clause.push(this.getPlaceholderForValue(j + 1));
}
}
ps.sql = clause.join('');
return ps;
};
/**
* Build the the `INSERT INTO` statement
* @param {String} model The model name
* @param {Object} fields Fields to be inserted
* @param {Object} options Options object
* @returns {ParameterizedSQL}
*/
SQLConnector.prototype.buildInsertInto = function(model, fields, options) {
var stmt = new ParameterizedSQL('INSERT INTO ' + this.tableEscaped(model));
var columnNames = fields.names.join(',');
if (columnNames) {
stmt.merge('(' + columnNames + ')', '');
}
return stmt;
};
/**
* Build the clause to return id values after insert
* @param {String} model The model name
* @param {Object} data The model data object
* @param {Object} options Options object
* @returns {string}
*/
SQLConnector.prototype.buildInsertReturning = function(model, data, options) {
return '';
};
/**
* Build the clause for default values if the fields is empty
* @param {String} model The model name
* @param {Object} data The model data object
* @param {Object} options Options object
* @returns {string} 'DEFAULT VALUES'
*/
SQLConnector.prototype.buildInsertDefaultValues = function(model, data, options) {
return 'VALUES()';
};
/**
* Build INSERT SQL statement
* @param {String} model The model name
* @param {Object} data The model data object
* @param {Object} options The options object
* @returns {string} The INSERT SQL statement
*/
SQLConnector.prototype.buildInsert = function(model, data, options) {
var fields = this.buildFields(model, data);
var insertStmt = this.buildInsertInto(model, fields, options);
var columnValues = fields.columnValues;
var fieldNames = fields.names;
if (fieldNames.length) {
var values = ParameterizedSQL.join(columnValues, ',');
values.sql = 'VALUES(' + values.sql + ')';
insertStmt.merge(values);
} else {
insertStmt.merge(this.buildInsertDefaultValues(model, data, options));
}
var returning = this.buildInsertReturning(model, data, options);
if (returning) {
insertStmt.merge(returning);
}
return this.parameterize(insertStmt);
};
/**
* Execute a SQL statement with given parameters.
*
* @param {String} sql The SQL statement
* @param {*[]} [params] An array of parameter values
* @param {Object} [options] Options object
* @param {Function} [callback] The callback function
*/
SQLConnector.prototype.execute = function(sql, params, options, callback) {
assert(typeof sql === 'string', 'sql must be a string');
if (typeof params === 'function' && options === undefined &&
callback === undefined) {
// execute(sql, callback)
options = {};
callback = params;
params = [];
} else if (typeof options === 'function' && callback === undefined) {
// execute(sql, params, callback)
callback = options;
options = {};
}
params = params || [];
options = options || {};
assert(Array.isArray(params), 'params must be an array');
assert(typeof options === 'object', 'options must be an object');
assert(typeof callback === 'function', 'callback must be a function');
var self = this;
if (!this.dataSource.connected) {
return this.dataSource.once('connected', function() {
self.execute(sql, params, options, callback);
});
}
var context = {
req: {
sql: sql,
params: params
},
options: options
};
this.notifyObserversAround('execute', context, function(context, done) {
self.executeSQL(context.req.sql, context.req.params, context.options, function(err, info) {
if (!err && info != null) {
context.res = info;
}
// Don't pass more than one args as it will confuse async.waterfall
done(err, info);
});
}, callback);
};
/**
* Create the data model in MySQL
*
* @param {String} model The model name
* @param {Object} data The model instance data
* @param {Object} options Options object
* @param {Function} [callback] The callback function
*/
SQLConnector.prototype.create = function(model, data, options, callback) {
var self = this;
var stmt = this.buildInsert(model, data, options);
this.execute(stmt.sql, stmt.params, options, function(err, info) {
if (err) {
callback(err);
} else {
var insertedId = self.getInsertedId(model, info);
callback(err, insertedId);
}
});
};
/**
* Save the model instance into the database
* @param {String} model The model name
* @param {Object} data The model instance data
* @param {Object} options Options object
* @param {Function} cb The callback function
*/
SQLConnector.prototype.save = function(model, data, options, cb) {
var idName = this.idName(model);
var idValue = data[idName];
if (!isIdValuePresent(idValue, cb)) {
return;
}
var where = {};
where[idName] = idValue;
var updateStmt = new ParameterizedSQL('UPDATE ' + this.tableEscaped(model));
updateStmt.merge(this.buildFieldsForUpdate(model, data));
var whereStmt = this.buildWhere(model, where);
updateStmt.merge(whereStmt);
updateStmt = this.parameterize(updateStmt);
this.execute(updateStmt.sql, updateStmt.params, options,
function(err, result) {
if (cb) cb(err, result);
});
};
/**
* Check if a model instance exists for the given id value
* @param {String} model The model name
* @param {*} id The id value
* @param {Object} options Options object
* @param {Function} cb The callback function
*/
SQLConnector.prototype.exists = function(model, id, options, cb) {
if (!isIdValuePresent(id, cb, true)) {
return;
}
var idName = this.idName(model);
var where = {};
where[idName] = id;
var selectStmt = new ParameterizedSQL(
'SELECT 1 FROM ' + this.tableEscaped(model) +
' WHERE ' + this.idColumnEscaped(model)
);
selectStmt.merge(this.buildWhere(model, where));
selectStmt = this.applyPagination(model, selectStmt, {
limit: 1,
offset: 0,
order: [idName]
});
selectStmt = this.parameterize(selectStmt);
this.execute(selectStmt.sql, selectStmt.params, options, function(err, data) {
if (!cb) return;
if (err) {
cb(err);
} else {
cb(null, data.length >= 1);
}
});
};
/**
* ATM, this method is not used by loopback-datasource-juggler dao, which
* maps `destroy` to `destroyAll` with a `where` filter that includes the `id`
* instead.
*
* Delete a model instance by id value
* @param {String} model The model name
* @param {*} id The id value
* @param {Object} options Options object
* @param {Function} cb The callback function
* @private
*/
SQLConnector.prototype.destroy = function(model, id, options, cb) {
if (!isIdValuePresent(id, cb, true)) {
return;
}
var idName = this.idName(model);
var where = {};
where[idName] = id;
this.destroyAll(model, where, options, cb);
};
// Alias to `destroy`. Juggler checks `destroy` only.
Connector.defineAliases(SQLConnector.prototype, 'destroy',
['delete', 'deleteById', 'destroyById']);
/**
* Build the `DELETE FROM` SQL statement
* @param {String} model The model name
* @param {Object} where The where object
* @param {Object} options Options object
* @returns {ParameterizedSQL} The SQL DELETE FROM statement
*/
SQLConnector.prototype.buildDelete = function(model, where, options) {
var deleteStmt = new ParameterizedSQL('DELETE FROM ' +
this.tableEscaped(model));
deleteStmt.merge(this.buildWhere(model, where));
return this.parameterize(deleteStmt);
};
/**
* Delete all matching model instances
*
* @param {String} model The model name
* @param {Object} where The where object
* @param {Object} options The options object
* @param {Function} cb The callback function
*/
SQLConnector.prototype.destroyAll = function(model, where, options, cb) {
var self = this;
var stmt = this.buildDelete(model, where, options);
this.execute(stmt.sql, stmt.params, options, function(err, info) {
var affectedRows = self.getCountForAffectedRows(model, info);
if (cb) {
cb(err, {count: affectedRows});
}
});
};
// Alias to `destroyAll`. Juggler checks `destroyAll` only.
Connector.defineAliases(SQLConnector.prototype, 'destroyAll', ['deleteAll']);
/**
* ATM, this method is not used by loopback-datasource-juggler dao, which
* maps `updateAttributes` to `update` with a `where` filter that includes the
* `id` instead.
*
* Update attributes for a given model instance
* @param {String} model The model name
* @param {*} id The id value
* @param {Object} data The model data instance containing all properties to
* be updated
* @param {Object} options Options object
* @param {Function} cb The callback function
* @private
*/
SQLConnector.prototype.updateAttributes = function(model, id, data, options, cb) {
if (!isIdValuePresent(id, cb)) {
return;
}
var idName = this.idName(model);
delete data[idName];
var where = {};
where[idName] = id;
this.updateAll(model, where, data, options, cb);
};
/**
* Build the UPDATE statement
* @param {String} model The model name
* @param {Object} where The where object
* @param {Object} data The data to be changed
* @param {Object} options The options object
* @param {Function} cb The callback function
* @returns {ParameterizedSQL} The UPDATE SQL statement
*/
SQLConnector.prototype.buildUpdate = function(model, where, data, options) {
var fields = this.buildFieldsForUpdate(model, data);
var updateClause = new ParameterizedSQL('UPDATE ' + this.tableEscaped(model));
var whereClause = this.buildWhere(model, where);
updateClause.merge([fields, whereClause]);
return this.parameterize(updateClause);
};
/**
* Update all instances that match the where clause with the given data
* @param {String} model The model name
* @param {Object} where The where object
* @param {Object} data The property/value object representing changes
* to be made
* @param {Object} options The options object
* @param {Function} cb The callback function
*/
SQLConnector.prototype.update = function(model, where, data, options, cb) {
var self = this;
var stmt = this.buildUpdate(model, where, data, options);
this.execute(stmt.sql, stmt.params, options, function(err, info) {
var affectedRows = self.getCountForAffectedRows(model, info);
if (cb) {
cb(err, {count: affectedRows});
}
});
};
// Alias to `update`. Juggler checks `update` only.
Connector.defineAliases(SQLConnector.prototype, 'update', ['updateAll']);
/**
* Build the SQL WHERE clause for the where object
* @param {string} model Model name
* @param {object} where An object for the where conditions
* @returns {ParameterizedSQL} The SQL WHERE clause
*/
SQLConnector.prototype.buildWhere = function(model, where) {
var whereClause = this._buildWhere(model, where);
if (whereClause.sql) {
whereClause.sql = 'WHERE ' + whereClause.sql;
}
return whereClause;
};
/**
* Build SQL expression
* @param {String} columnName Escaped column name
* @param {String} operator SQL operator
* @param {*} columnValue Column value
* @param {*} propertyValue Property value
* @returns {ParameterizedSQL} The SQL expression
*/
SQLConnector.prototype.buildExpression = function(columnName, operator, columnValue, propertyValue) {
function buildClause(columnValue, separator, grouping) {
var values = [];
for (var i = 0, n = columnValue.length; i < n; i++) {
if (columnValue[i] instanceof ParameterizedSQL) {
values.push(columnValue[i]);
} else {
values.push(new ParameterizedSQL(PLACEHOLDER, [columnValue[i]]));
}
}
separator = separator || ',';
var clause = ParameterizedSQL.join(values, separator);
if (grouping) {
clause.sql = '(' + clause.sql + ')';
}
return clause;
}
var sqlExp = columnName;
var clause;
if (columnValue instanceof ParameterizedSQL) {
clause = columnValue;
} else {
clause = new ParameterizedSQL(PLACEHOLDER, [columnValue]);
}
switch (operator) {
case 'gt':
sqlExp += '>';
break;
case 'gte':
sqlExp += '>=';
break;
case 'lt':
sqlExp += '<';
break;
case 'lte':
sqlExp += '<=';
break;
case 'between':
sqlExp += ' BETWEEN ';
clause = buildClause(columnValue, ' AND ', false);
break;
case 'inq':
sqlExp += ' IN ';
clause = buildClause(columnValue, ',', true);
break;
case 'nin':
sqlExp += ' NOT IN ';
clause = buildClause(columnValue, ',', true);
break;
case 'neq':
if (columnValue == null) {
return new ParameterizedSQL(sqlExp + ' IS NOT NULL');
}
sqlExp += '!=';
break;
case 'like':
sqlExp += ' LIKE ';
break;
case 'nlike':
sqlExp += ' NOT LIKE ';
break;
case 'regexp':
sqlExp += ' REGEXP ';
break;
}
var stmt = ParameterizedSQL.join([sqlExp, clause], '');
return stmt;
};
/*!
* @param model
* @param where
* @returns {ParameterizedSQL}
* @private
*/
SQLConnector.prototype._buildWhere = function(model, where) {
if (!where) {
return new ParameterizedSQL('');
}
if (typeof where !== 'object' || Array.isArray(where)) {
debug('Invalid value for where: %j', where);
return new ParameterizedSQL('');
}
var self = this;
var props = self.getModelDefinition(model).properties;
var whereStmts = [];
for (var key in where) {
var stmt = new ParameterizedSQL('', []);
// Handle and/or operators
if (key === 'and' || key === 'or') {
var branches = [];
var branchParams = [];
var clauses = where[key];
if (Array.isArray(clauses)) {
for (var i = 0, n = clauses.length; i < n; i++) {
var stmtForClause = self._buildWhere(model, clauses[i]);
stmtForClause.sql = '(' + stmtForClause.sql + ')';
branchParams = branchParams.concat(stmtForClause.params);
branches.push(stmtForClause.sql);
}
stmt.merge({
sql: branches.join(' ' + key.toUpperCase() + ' '),
params: branchParams
});
whereStmts.push(stmt);
continue;
}
// The value is not an array, fall back to regular fields
}
var columnName = self.columnEscaped(model, key);
var expression = where[key];
var columnValue;
var sqlExp;
if (expression === null || expression === undefined) {
stmt.merge(columnName + ' IS NULL');
} else if (expression && expression.constructor === Object) {
var operator = Object.keys(expression)[0];
// Get the expression without the operator
expression = expression[operator];
if (operator === 'inq' || operator === 'nin' || operator === 'between') {
columnValue = [];
if (Array.isArray(expression)) {
// Column value is a list
for (var j = 0, m = expression.length; j < m; j++) {
columnValue.push(this.toColumnValue(props[key], expression[j]));
}
} else {
columnValue.push(this.toColumnValue(props[key], expression));
}
if (operator === 'between') {
// BETWEEN v1 AND v2
var v1 = columnValue[0] === undefined ? null : columnValue[0];
var v2 = columnValue[1] === undefined ? null : columnValue[1];
columnValue = [v1, v2];
} else {
// IN (v1,v2,v3) or NOT IN (v1,v2,v3)
if (columnValue.length === 0) {
if (operator === 'inq') {
columnValue = [null];
} else {
// nin () is true
continue;
}
}
}
} else {
columnValue = this.toColumnValue(props[key], expression);
}
sqlExp = self.buildExpression(
columnName, operator, columnValue, props[key]);
stmt.merge(sqlExp);
} else {
// The expression is the field value, not a condition
columnValue = self.toColumnValue(props[key], expression);
if (columnValue === null) {
stmt.merge(columnName + ' IS NULL');
} else {
if (columnValue instanceof ParameterizedSQL) {
stmt.merge(columnName + '=').merge(columnValue);
} else {
stmt.merge({
sql: columnName + '=?',
params: [columnValue]
});
}
}
}
whereStmts.push(stmt);
}
var params = [];
var sqls = [];
for (var k = 0, s = whereStmts.length; k < s; k++) {
sqls.push(whereStmts[k].sql);
params = params.concat(whereStmts[k].params);
}
var whereStmt = new ParameterizedSQL({
sql: sqls.join(' AND '),
params: params
});
return whereStmt;
};
/**
* Build the ORDER BY clause
* @param {string} model Model name
* @param {string[]} order An array of sorting criteria
* @returns {string} The ORDER BY clause
*/
SQLConnector.prototype.buildOrderBy = function(model, order) {
if (!order) {
return '';
}
var self = this;
if (typeof order === 'string') {
order = [order];
}
var clauses = [];
for (var i = 0, n = order.length; i < n; i++) {
var t = order[i].split(/[\s,]+/);
if (t.length === 1) {
clauses.push(self.columnEscaped(model, order[i]));
} else {
clauses.push(self.columnEscaped(model, t[0]) + ' ' + t[1]);
}
}
return 'ORDER BY ' + clauses.join(',');
};
/**
* Build an array of fields for the database operation
* @param {String} model Model name
* @param {Object} data Model data object
* @param {Boolean} excludeIds Exclude id properties or not, default to false
* @returns {{names: Array, values: Array, properties: Array}}
*/
SQLConnector.prototype.buildFields = function(model, data, excludeIds) {
var fields = {
names: [], // field names
columnValues: [], // an array of ParameterizedSQL
properties: [] // model properties
};
var props = this.getModelDefinition(model).properties;
var keys = Object.keys(data);
for (var i = 0, n = keys.length; i < n; i++) {
var key = keys[i];
var p = props[key];
if (p == null) {
// Unknown property, ignore it
debug('Unknown property %s is skipped for model %s', key, model);
continue;
}
if (excludeIds && p.id) {
continue;
}
var k = this.columnEscaped(model, key);
var v = this.toColumnValue(p, data[key]);
if (v !== undefined) {
fields.names.push(k);
if (v instanceof ParameterizedSQL) {
fields.columnValues.push(v);
} else {
fields.columnValues.push(new ParameterizedSQL(PLACEHOLDER, [v]));
}
fields.properties.push(p);
}
}
return fields;
};
/**
* Build the SET clause for database update
* @param {String} model Model na
* @param {Object} data The model data object
* @param {Boolean} excludeIds Exclude id properties or not, default to true
* @returns {string} The list of fields for update
*/
SQLConnector.prototype.buildFieldsForUpdate = function(model, data, excludeIds) {
if (excludeIds === undefined) {
excludeIds = true;
}
var fields = this.buildFields(model, data, excludeIds);
var columns = new ParameterizedSQL('');
for (var i = 0, n = fields.names.length; i < n; i++) {
var clause = ParameterizedSQL.append(fields.names[i],
fields.columnValues[i], '=');
columns.merge(clause, ',');
}
columns.sql = 'SET ' + columns.sql;
return columns;
};
/**
* Build a list of escaped column names for the given model and fields filter
* @param {string} model Model name
* @param {object} filter The filter object
* @returns {string} Comma separated string of escaped column names
*/
SQLConnector.prototype.buildColumnNames = function(model, filter) {
var fieldsFilter = filter && filter.fields;
var cols = this.getModelDefinition(model).properties;
if (!cols) {
return '*';
}
var self = this;
var keys = Object.keys(cols);
if (Array.isArray(fieldsFilter) && fieldsFilter.length > 0) {
// Not empty array, including all the fields that are valid properties
keys = fieldsFilter.filter(function(f) {
return cols[f];
});
} else if ('object' === typeof fieldsFilter &&
Object.keys(fieldsFilter).length > 0) {
// { field1: boolean, field2: boolean ... }
var included = [];
var excluded = [];
keys.forEach(function(k) {
if (fieldsFilter[k]) {
included.push(k);
} else if ((k in fieldsFilter) && !fieldsFilter[k]) {
excluded.push(k);
}
});
if (included.length > 0) {
keys = included;
} else if (excluded.length > 0) {
excluded.forEach(function(e) {
var index = keys.indexOf(e);
keys.splice(index, 1);
});
}
}
var names = keys.map(function(c) {
return self.columnEscaped(model, c);
});
return names.join(',');
};
/**
* Build a SQL SELECT statement
* @param {String} model Model name
* @param {Object} filter Filter object
* @param {Object} options Options object
* @returns {ParameterizedSQL} Statement object {sql: ..., params: [...]}
*/
SQLConnector.prototype.buildSelect = function(model, filter, options) {
if (!filter.order) {
var idNames = this.idNames(model);
if (idNames && idNames.length) {
filter.order = idNames;
}
}
var selectStmt = new ParameterizedSQL('SELECT ' +
this.buildColumnNames(model, filter) +
' FROM ' + this.tableEscaped(model)
);
if (filter) {
if (filter.where) {
var whereStmt = this.buildWhere(model, filter.where);
selectStmt.merge(whereStmt);
}
if (filter.order) {
selectStmt.merge(this.buildOrderBy(model, filter.order));
}
if (filter.limit || filter.skip || filter.offset) {
selectStmt = this.applyPagination(
model, selectStmt, filter);
}
}
return this.parameterize(selectStmt);
};
/**
* Transform the row data into a model data object
* @param {string} model Model name
* @param {object} rowData An object representing the row data from DB
* @returns {object} Model data object
*/
SQLConnector.prototype.fromRow = SQLConnector.prototype.fromDatabase = function(model, rowData) {
if (rowData == null) {
return rowData;
}
var props = this.getModelDefinition(model).properties;
var data = {};
for (var p in props) {
var columnName = this.column(model, p);
// Load properties from the row
var columnValue = this.fromColumnValue(props[p], rowData[columnName]);
if (columnValue !== undefined) {
data[p] = columnValue;
}
}
return data;
};
/**
* Find matching model instances by the filter
*
* Please also note the name `all` is confusing. `Model.find` is to find all
* matching instances while `Model.findById` is to find an instance by id. On
* the other hand, `Connector.prototype.all` implements `Model.find` while
* `Connector.prototype.find` implements `Model.findById` due to the `bad`
* naming convention we inherited from juggling-db.
*
* @param {String} model The model name
* @param {Object} filter The filter
* @param {Function} [cb] The cb function
*/
SQLConnector.prototype.all = function find(model, filter, options, cb) {
var self = this;
// Order by id if no order is specified
filter = filter || {};
var stmt = this.buildSelect(model, filter, options);
this.execute(stmt.sql, stmt.params, options, function(err, data) {
if (err) {
return cb(err, []);
}
var objs = data.map(function(obj) {
return self.fromRow(model, obj);
});
if (filter && filter.include) {
self.getModelDefinition(model).model.include(
objs, filter.include, options, cb);
} else {
cb(null, objs);
}
});
};
// Alias to `all`. Juggler checks `all` only.
Connector.defineAliases(SQLConnector.prototype, 'all', ['findAll']);
/**
* ATM, this method is not used by loopback-datasource-juggler dao, which
* maps `findById` to `find` with a `where` filter that includes the `id`
* instead.
*
* Please also note the name `find` is confusing. `Model.find` is to find all
* matching instances while `Model.findById` is to find an instance by id. On
* the other hand, `Connector.prototype.find` is for `findById` and
* `Connector.prototype.all` is for `find` due the `bad` convention used by
* juggling-db.
*
* Find by id
* @param {String} model The Model name
* @param {*} id The id value
* @param {Object} options The options object
* @param {Function} cb The callback function
* @private
*/
SQLConnector.prototype.find = function(model, id, options, cb) {
if (id == null) {
process.nextTick(function() {
var err = new Error('id value is required');
if (cb) {
cb(err);
}
});
return;
}
var where = {};
var idName = this.idName(model);
where[idName] = id;
var filter = {limit: 1, offset: 0, order: idName, where: where};
return this.all(model, filter, options, function(err, results) {
cb(err, (results && results[0]) || null);
});
};
// Alias to `find`. Juggler checks `findById` only.
Connector.defineAliases(SQLConnector.prototype, 'find', ['findById']);
/**
* Count all model instances by the where filter
*
* @param {String} model The model name
* @param {Object} where The where object
* @param {Object} options The options object
* @param {Function} cb The callback function
*/
SQLConnector.prototype.count = function(model, where, options, cb) {
if (typeof where === 'function') {
// Backward compatibility for 1.x style signature:
// count(model, cb, where)
var tmp = options;
cb = where;
where = tmp;
}
var stmt = new ParameterizedSQL('SELECT count(*) as "cnt" FROM ' +
this.tableEscaped(model));
stmt = stmt.merge(this.buildWhere(model, where));
stmt = this.parameterize(stmt);
this.execute(stmt.sql, stmt.params,
function(err, res) {
if (err) {
return cb(err);
}
var c = (res && res[0] && res[0].cnt) || 0;
// Some drivers return count as a string to contain bigint
// See https://github.com/brianc/node-postgres/pull/427
cb(err, Number(c));
});
};
/**
* Drop the table for the given model from the database
* @param {String} model The model name
* @param {Function} [cb] The callback function
*/
SQLConnector.prototype.dropTable = function(model, cb) {
this.execute('DROP TABLE IF EXISTS ' + this.tableEscaped(model), cb);
};
/**
* Create the table for the given model
* @param {String} model The model name
* @param {Function} [cb] The callback function
*/
SQLConnector.prototype.createTable = function(model, cb) {
var sql = 'CREATE TABLE ' + this.tableEscaped(model) +
' (\n ' + this.buildColumnDefinitions(model) + '\n)';
this.execute(sql, cb);
};
/**
* Recreate the tables for the given models
* @param {[String]|String} [models] A model name or an array of model names,
* if not present, apply to all models defined in the connector
* @param {Function} [cb] The callback function
*/
SQLConnector.prototype.automigrate = function(models, cb) {
var self = this;
if ((!cb) && ('function' === typeof models)) {
cb = models;
models = undefined;
}
// First argument is a model name
if ('string' === typeof models) {
models = [models];
}
models = models || Object.keys(self._models);
if (models.length === 0) {
return process.nextTick(cb);
}
var invalidModels = models.filter(function(m) {
return !(m in self._models);
});
if (invalidModels.length) {
return process.nextTick(function() {
cb(new Error('Cannot migrate models not attached to this datasource: ' +
invalidModels.join(' ')));
});
}
async.each(models, function(model, done) {
self.dropTable(model, function(err) {
if (err) {
// TODO(bajtos) should we abort here and call cb(err)?
// The original code in juggler ignored the error completely
console.error(err);
}
self.createTable(model, function(err, result) {
if (err) {
console.error(err);
}
done(err, result);
});
});
}, cb);
};
/**
* Serialize an object into JSON string or other primitive types so that it
* can be saved into a RDB column
* @param {Object} obj The object value
* @returns {*}
*/
SQLConnector.prototype.serializeObject = function(obj) {
var val;
if (obj && typeof obj.toJSON === 'function') {
obj = obj.toJSON();
}
if (typeof obj !== 'string') {
val = JSON.stringify(obj);
} else {
val = obj;
}
return val;
};
/*!
* @param obj
*/
SQLConnector.prototype.escapeObject = function(obj) {
var val = this.serializeObject(obj);
return this.escapeValue(val);
};
/**
* The following _abstract_ methods have to be implemented by connectors that
* extend from SQLConnector to reuse the base implementations of CRUD methods
* from SQLConnector
*/
/**
* Converts a model property value into the form required by the
* database column. The result should be one of following forms:
*
* - {sql: "point(?,?)", params:[10,20]}
* - {sql: "'John'", params: []}
* - "John"
*
* @param {Object} propertyDef Model property definition
* @param {*} value Model property value
* @returns {ParameterizedSQL|*} Database column value.
*
*/
SQLConnector.prototype.toColumnValue = function(propertyDef, value) {
throw new Error('toColumnValue() must be implemented by the connector');
};
/**
* Convert the data from database column to model property
* @param {object} propertyDef Model property definition
* @param {*) value Column value
* @returns {*} Model property value
*/
SQLConnector.prototype.fromColumnValue = function(propertyDef, value) {
throw new Error('fromColumnValue() must be implemented by the connector');
};
/**
* Escape the name for the underlying database
* @param {String} name The name
* @returns {String} An escaped name for SQL
*/
SQLConnector.prototype.escapeName = function(name) {
throw new Error('escapeName() must be implemented by the connector');
};
/**
* Escape the name for the underlying database
* @param {String} value The value to be escaped
* @returns {*} An escaped value for SQL
*/
SQLConnector.prototype.escapeValue = function(value) {
throw new Error('escapeValue() must be implemented by the connector');
};
/**
* Get the place holder in SQL for identifiers, such as ??
* @param {String} key Optional key, such as 1 or id
* @returns {String} The place holder
*/
SQLConnector.prototype.getPlaceholderForIdentifier = function(key) {
throw new Error('getPlaceholderForIdentifier() must be implemented by the connector');
};
/**
* Get the place holder in SQL for values, such as :1 or ?
* @param {String} key Optional key, such as 1 or id
* @returns {String} The place holder
*/
SQLConnector.prototype.getPlaceholderForValue = function(key) {
throw new Error('getPlaceholderForValue() must be implemented by the connector');
};
/**
* Build a new SQL statement with pagination support by wrapping the given sql
* @param {String} model The model name
* @param {ParameterizedSQL} stmt The sql statement
* @param {Object} filter The filter object from the query
*/
SQLConnector.prototype.applyPagination = function(model, stmt, filter) {
throw new Error('applyPagination() must be implemented by the connector');
};
/**
* Parse the result for SQL UPDATE/DELETE/INSERT for the number of rows
* affected
* @param {String} model Model name
* @param {Object} info Status object
* @returns {Number} Number of rows affected
*/
SQLConnector.prototype.getCountForAffectedRows = function(model, info) {
throw new Error('getCountForAffectedRows() must be implemented by the connector');
};
/**
* Parse the result for SQL INSERT for newly inserted id
* @param {String} model Model name
* @param {Object} info The status object from driver
* @returns {*} The inserted id value
*/
SQLConnector.prototype.getInsertedId = function(model, info) {
throw new Error('getInsertedId() must be implemented by the connector');
};
/**
* Execute a SQL statement with given parameters
* @param {String} sql The SQL statement
* @param {*[]} [params] An array of parameter values
* @param {Object} [options] Options object
* @param {Function} [callback] The callback function
*/
SQLConnector.prototype.executeSQL = function(sql, params, options, callback) {
throw new Error('executeSQL() must be implemented by the connector');
};