56 lines
1.7 KiB
JavaScript
56 lines
1.7 KiB
JavaScript
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var Transaction = require('loopback-connector').Transaction;
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module.exports = TransactionMixin;
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function TransactionMixin() {
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}
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/**
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* Begin a new transaction
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* @param {Object|String} [options] Options can be one of the forms:
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* - Object: {isolationLevel: '...', timeout: 1000}
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* - String: isolationLevel
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*
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* Valid values of `isolationLevel` are:
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*
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* - Transaction.READ_COMMITTED = 'READ COMMITTED'; // default
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* - Transaction.READ_UNCOMMITTED = 'READ UNCOMMITTED';
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* - Transaction.SERIALIZABLE = 'SERIALIZABLE';
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* - Transaction.REPEATABLE_READ = 'REPEATABLE READ';
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*
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* @param {Function} cb Callback function. It calls back with (err, transaction).
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* To pass the transaction context to one of the CRUD methods, use the `options`
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* argument with `transaction` property, for example,
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*
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* ```js
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*
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* MyModel.beginTransaction('READ COMMITTED', function(err, tx) {
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* MyModel.create({x: 1, y: 'a'}, {transaction: tx}, function(err, inst) {
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* MyModel.find({x: 1}, {transaction: tx}, function(err, results) {
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* // ...
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* tx.commit(function(err) {...});
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* });
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* });
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* });
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* ```
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*
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* The transaction can be committed or rolled back. If timeout happens, the
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* transaction will be rolled back. Please note a transaction is typically
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* associated with a pooled connection. Committing or rolling back a transaction
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* will release the connection back to the pool.
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*
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*/
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TransactionMixin.beginTransaction = function(options, cb) {
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if (Transaction) {
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var connector = this.getConnector();
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Transaction.begin(connector, options, cb);
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} else {
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process.nextTick(function() {
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var err = new Error('Transaction is not supported');
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cb(err);
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});
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}
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};
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