DDL.js API Documentation

Ddl

• .postgresql(connection, tableName, callback)
• .postgresqlSync(connection, tableName)
• .sqlite3(connection, tableName, callback)

Attribute

• default
• maxLength
• type

Ddl

The object returned by the per-database functions below that contains all of a table's columns with the column name as the key and an Attribute object as the value.

All columns of the table are set as enumerable properties of the object. To go over them, just use a for in loop.

Examples:

Ddl.sqlite3(db, "people", function(err, ddl) {
  for (name in ddl) console.log(name, ddl[name].type)
})

Ddl.postgresql(connection, tableName, callback)

Queries a PostgreSQL database table for its data definition.

Give it a Pg.Client for connection.
Calls callback with an error and a Ddl object with attributes.

Examples:

var Ddl = require("ddl")
var Pg = require("pg")

var db = new Pg.Client("postgresql://localhost/world")
db.connect()

Ddl.postgresql(db, "people", console.log)

Ddl.postgresqlSync(connection, tableName)

Queries a PostgreSQL database table for its data definition synchronously.

Give it a native PgClient for connection.
Returns a Ddl object with attributes.

Examples:

var Ddl = require("ddl")
var Pg = require("pg-native")

var db = new Pg
db.connectSync("postgresql://localhost/world")

Ddl.postgresqlSync(db, "people")

Ddl.sqlite3(connection, tableName, callback)

Queries a SQLite3 database table for its data definition.

Give it a Sqlite3.Database for connection.
Calls callback with an error and a Ddl object with attributes.

Examples:

var Ddl = require("ddl")
var Sqlite3 = require("sqlite3")
var db = new Sqlite3.Database("database.sqlite3")

Ddl.sqlite3(db, "people", console.log)

Attribute

The object specifying all properties of a single attribute or database column.

attribute.default

Default value for the column already cast to the column type.

Note: Only simple expressions are parsed and cast for now. Unsupported defaults are set to undefined.

Only simple defaults are supported because databases store defaults as you typed them to CREATE TABLE without evaluation or normalization. They get evaluated only when you actually insert rows. That makes it possible for you to set defaults to date('now'), but obviously makes it not-straightforward to read them back out.

If the default value's format is not supported, it'll be set to undefined. For the most part that is the safest thing — this way when you're later inserting data, leave out undefined columns and they'll be properly set by the database.

Column SQL	Default
INTEGER DEFAULT 30	30
VARCHAR DEFAULT 'Smith'	"Smith"
BOOLEAN DEFAULT 't'	true

attribute.maxLength

For string types with a limit it's the maximum number of characters allowed. Otherwise not set.

Column SQL	Limit
VARCHAR(60)	60
INTEGER	not set

attribute.type

Closest JavaScript type for the SQL type.

Either the type as a string (e.g. "number") or, should the column allow NULL values, an array with the type and "null" (e.g. ["number", "null"]).

Column SQL	Type
VARCHAR(60)	"string"
REAL	"number"
NUMERIC	"number"
SMALLINT	"integer"
INTEGER	"integer"
BIGINT	"integer"
BOOLEAN	"boolean"
DATETIME	"string"
DATE	"string"
JSON	"object"
JSONB	"object"