clients/server/postgres/grammar.js

PostgreSQL Grammar

var _ = require('lodash'); var Helpers = require('../../../lib/helpers').Helpers; var baseGrammar = require('../../base/grammar').baseGrammar;

Extends the standard sql grammar.

exports.grammar = _.defaults({

The keyword identifier wrapper format.

wrapValue: function(value) { return (value !== '*' ? Helpers.format('"%s"', value) : "*"); },

Compiles a truncate query.

compileTruncate: function(qb) { return 'truncate ' + this.wrapTable(qb.table) + ' restart identity'; },

Compiles an insert query, allowing for multiple inserts using a single query statement.

compileInsert: function(qb) { var values = qb.values; var columns = _.pluck(values[0], 0); var paramBlocks = [];

If there are any "where" clauses, we need to omit any bindings that may have been associated with them.

if (qb.wheres.length > 0) this.clearWhereBindings(qb); var sql = 'insert into ' + this.wrapTable(qb.table) + ' '; if (columns.length === 0) { sql += 'default values'; } else { for (var i = 0, l = values.length; i < l; ++i) { paramBlocks.push("(" + this.parameterize(_.pluck(values[i], 1)) + ")"); } sql += "(" + this.columnize(columns) + ") values " + paramBlocks.join(', '); } sql += this.compileReturning(qb); return sql; },

Compiles an update query, allowing for a return value.

compileUpdate: function(qb) { var sql = baseGrammar.compileUpdate.apply(this, arguments); sql += this.compileReturning(qb); return sql; },

Adds the returning value to the statement.

compileReturning: function(qb) { var sql = ''; if (qb.flags.returning) { if (_.isArray(qb.flags.returning)) { sql += ' returning ' + this.wrapArray(qb.flags.returning); } else { sql += ' returning ' + this.wrapValue(qb.flags.returning); } } return sql; },

Ensures the response is returned in the same format as other clients.

handleResponse: function(builder, response) { var returning = builder.flags.returning; if (response.command === 'SELECT') return response.rows; if (response.command === 'INSERT' || (response.command === 'UPDATE' && returning)) { return _.map(response.rows, function(row) { if (returning === '*' || _.isArray(returning)) return row; return row[returning]; }); } if (response.command === 'UPDATE' || response.command === 'DELETE') { return response.rowCount; } return ''; } }, baseGrammar);