Database

Module	ejs.db
Definition	class Database
Inheritance	Database Object
Specified	ejscript-2.5
Stability	Evolving.

SQL Database support.

The Database class provides an interface over other database adapter classes such as SQLite or MySQL. Not all the functionality expressed by this API may be implemented by a specific database adapter.

Properties

Qualifiers	Property	Type	Description
get	connectionOptions	Object	The database connection options 8.
static get set	defaultDatabase	Database	The default database for the application.
get	name	String	The name of the database.

Inherited Properties

Database Class Methods

(No own class methods defined)

Qualifiers	Method

Inherited Methods

Database Instance Methods

Qualifiers	Method
	Database(adapter: String, options: Object)
	Initialize a database connection using the supplied database connection string.
	addColumn(table: String, column: String, datatype: String, options = null): Void
	Add a column to a table.
	addIndex(table: String, column: String, index: String): Void
	Add an index on a column.
	changeColumn(table: String, column: String, datatype: String, options: Object = null): Void
	Change a column.
	close(): Void
	Close the database connection.
	createDatabase(name: String, options: Object = null): Void
	Create a new database.
	createTable(table: String, columns: Array = null): Void
	Create a new table.
	dataTypeToSqlType(dataType: String): String
	Map the database independant data type to a database dependant SQL data type.
	destroyDatabase(name: String): Void
	Destroy a database.
	destroyTable(table: String): Void
	Destroy a table.
	getColumns(table: String): Array
	Get column information.
	getNumRows(table: String): Number
	Return the number of rows in a table.
	getTables(): Array
	Return list of tables in a database.
	query(cmd: String, tag: String = SQL, trace: Boolean = false): Array
	Execute a SQL command on the database.
	removeColumns(table: String, columns: Array): Void
	Remove columns from a table.
	removeIndex(table: String, index: String): Void
	Remove an index.
	renameColumn(table: String, oldColumn: String, newColumn: String): Void
	Rename a column.
	renameTable(oldTable: String, newTable: String): Void
	Rename a table.
	sql(cmd: String): Array
	Execute a SQL command on the database.
	sqlTypeToDataType(sqlType: String): String
	Map the SQL type to a database independant data type.
	sqlTypeToEjsType(sqlType: String): Type
	Map the SQL type to an Ejscript type class.
	trace(on: Boolean): Void
	Trace all SQL statements on this database.

Inherited Methods

Method Detail

ejs.db Database(adapter: String, options: Object)

Description: Initialize a database connection using the supplied database connection string. The first opened database will also be defined as the default database.

Parameters

adapter: String	Database adapter to use. E.g. "sqlite". Sqlite is currently the only supported adapter.
options: Object	Connection options. This may be filename or an object hash of properties. If set to a filename, it should contain the filename of the database on the local system. If options is an object hash, it should contain adapter specific properties that specify how to attach to the database.

Options

name	Database name.
username	Database username.
password	Database password.
trace	Trace database commands to the log.
socket	Database communications socket.
module	Module name containing the database connector class. This is a bare module name without ".mod" or any leading path.
class	Class name containing the database backend.

addColumn(table: String, column: String, datatype: String, options = null): Void

Description: Add a column to a table.

Parameters

table: String	Name of the table.
column: String	Name of the column to add.
datatype: String	Database independant type of the column. Valid types are: binary, boolean, date, datetime, decimal, float, integer, number, string, text, time and timestamp.
options	Optional parameters. [default: null]

addIndex(table: String, column: String, index: String): Void

Description: Add an index on a column.

Parameters

table: String	Name of the table.
column: String	Name of the column to add.
index: String	Name of the index.

changeColumn(table: String, column: String, datatype: String, options: Object = null): Void

Description: Change a column.

Parameters

table: String	Name of the table holding the column.
column: String	Name of the column to change.
datatype: String	Database independant type of the column. Valid types are: binary, boolean, date, datetime, decimal, float, integer, number, string, text, time and timestamp.
options: Object	Optional parameters. [default: null]

close(): Void

Description: Close the database connection. Database connections should be closed when no longer needed rather than waiting for the garbage collector to automatically close the connection when disposing the database instance.

createDatabase(name: String, options: Object = null): Void

Description: Create a new database.

Parameters

name: String	Name of the database.
options: Object	null [default: null]

Options

Optional

Parameters.

createTable(table: String, columns: Array = null): Void

Description: Create a new table.

Parameters

table: String	Name of the table.
columns: Array	Array of column descriptor tuples consisting of name:datatype. [default: null]

dataTypeToSqlType(dataType: String): String

Description: Map the database independant data type to a database dependant SQL data type.

Parameters

dataType: String

Data type to map.

Returns: A string containing the name of the the corresponding SQL database type.

destroyDatabase(name: String): Void

Description: Destroy a database.

Parameters

name: String

Name of the database to remove.

destroyTable(table: String): Void

Description: Destroy a table.

Parameters

table: String

Name of the table to destroy.

getColumns(table: String): Array

Description: Get column information.

Parameters

table: String

Name of the table to examine.

Returns: An array of column data. This is database specific content and will vary depending on the database connector in use.

getNumRows(table: String): Number

Description: Return the number of rows in a table.

Returns: The count of rows in a table in the currently opened database.

getTables(): Array

Description: Return list of tables in a database.

Returns: An array containing list of table names present in the currently opened database.

query(cmd: String, tag: String = SQL, trace: Boolean = false): Array

Description: Execute a SQL command on the database.

Parameters

cmd: String	SQL command string.
tag: String	Debug tag to use when logging the command. [default: SQL]
trace: Boolean	Set to true to eanble logging this command. [default: false]

Returns: An array of row results where each row is represented by an Object hash containing the column names and values.

removeColumns(table: String, columns: Array): Void

Description: Remove columns from a table.

Parameters

table: String	Name of the table to modify.
columns: Array	Array of column names to remove.

removeIndex(table: String, index: String): Void

Description: Remove an index.

Parameters

table: String	Name of the table to modify.
index: String	Name of the index to remove.

renameColumn(table: String, oldColumn: String, newColumn: String): Void

Description: Rename a column.

Parameters

table: String	Name of the table to modify.
oldColumn: String	Old column name.
newColumn: String	New column name.

renameTable(oldTable: String, newTable: String): Void

Description: Rename a table.

Parameters

oldTable: String	Old table name.
newTable: String	New table name.

sql(cmd: String): Array

Description: Execute a SQL command on the database. This is a low level SQL command interface that bypasses logging. Use.

Parameters

cmd: String

SQL command to issue. Note: "SELECT" is automatically prepended and ";" is appended for you.

Returns: An array of row results where each row is represented by an Object hash containing the column names and values.

sqlTypeToDataType(sqlType: String): String

Description: Map the SQL type to a database independant data type.

Parameters

sqlType: String

Data type to map.

Returns: The corresponding database independant type.

sqlTypeToEjsType(sqlType: String): Type

Description: Map the SQL type to an Ejscript type class.

Parameters

sqlType: String

Data type to map.

Returns: The corresponding type class.

trace(on: Boolean): Void

Description: Trace all SQL statements on this database. Control whether trace is enabled for all SQL statements issued against the database.

Parameters

on: Boolean

If true, display each SQL statement to the log.