result.js•2.73 kB
'use strict'
const types = require('pg-types')
const matchRegexp = /^([A-Za-z]+)(?: (\d+))?(?: (\d+))?/
// result object returned from query
// in the 'end' event and also
// passed as second argument to provided callback
class Result {
constructor(rowMode, types) {
this.command = null
this.rowCount = null
this.oid = null
this.rows = []
this.fields = []
this._parsers = undefined
this._types = types
this.RowCtor = null
this.rowAsArray = rowMode === 'array'
if (this.rowAsArray) {
this.parseRow = this._parseRowAsArray
}
this._prebuiltEmptyResultObject = null
}
// adds a command complete message
addCommandComplete(msg) {
let match
if (msg.text) {
// pure javascript
match = matchRegexp.exec(msg.text)
} else {
// native bindings
match = matchRegexp.exec(msg.command)
}
if (match) {
this.command = match[1]
if (match[3]) {
// COMMAND OID ROWS
this.oid = parseInt(match[2], 10)
this.rowCount = parseInt(match[3], 10)
} else if (match[2]) {
// COMMAND ROWS
this.rowCount = parseInt(match[2], 10)
}
}
}
_parseRowAsArray(rowData) {
const row = new Array(rowData.length)
for (let i = 0, len = rowData.length; i < len; i++) {
const rawValue = rowData[i]
if (rawValue !== null) {
row[i] = this._parsers[i](rawValue)
} else {
row[i] = null
}
}
return row
}
parseRow(rowData) {
const row = { ...this._prebuiltEmptyResultObject }
for (let i = 0, len = rowData.length; i < len; i++) {
const rawValue = rowData[i]
const field = this.fields[i].name
if (rawValue !== null) {
row[field] = this._parsers[i](rawValue)
} else {
row[field] = null
}
}
return row
}
addRow(row) {
this.rows.push(row)
}
addFields(fieldDescriptions) {
// clears field definitions
// multiple query statements in 1 action can result in multiple sets
// of rowDescriptions...eg: 'select NOW(); select 1::int;'
// you need to reset the fields
this.fields = fieldDescriptions
if (this.fields.length) {
this._parsers = new Array(fieldDescriptions.length)
}
const row = {}
for (let i = 0; i < fieldDescriptions.length; i++) {
const desc = fieldDescriptions[i]
row[desc.name] = null
if (this._types) {
this._parsers[i] = this._types.getTypeParser(desc.dataTypeID, desc.format || 'text')
} else {
this._parsers[i] = types.getTypeParser(desc.dataTypeID, desc.format || 'text')
}
}
this._prebuiltEmptyResultObject = { ...row }
}
}
module.exports = Result