CONNECT statement [ESQL] [Interactive SQL]

Use this statement to establish a connection to a database.

Syntax 1
CONNECT
[ TO database-server-name ]
[ DATABASE database-name ]
[ AS connection-name ]
[ USER ] userid [ IDENTIFIED BY password ]
database-server-name, database-name, connection-name, userid, password :
{ identifier | string | hostvar }
Syntax 2
CONNECT USING connect-string
connect-string : { identifier | string | hostvar }
Parameters
  • AS clause   A connection can optionally be named by specifying the AS clause. This allows multiple connections to the same database, or multiple connections to the same or different database servers, all simultaneously. Each connection has its own associated transaction. You may even get locking conflicts between your transactions if, for example, you try to modify the same record in the same database from two different connections.

Syntax 2   A connect-string is a list of parameter settings of the form keyword=value, separated by semicolons, and must be enclosed in single quotes.

For more information about connection strings, see Connection parameters.

Remarks

The CONNECT statement establishes a connection to the database identified by database-name running on the database server identified by database-server-name. This statement is not supported in procedures, triggers, events, or batches.

Embedded SQL behavior   In embedded SQL, if no database-server-name is specified, the default local database server is assumed (the first database server started). If no database-name is specified, the first database on the given server is assumed.

The WHENEVER statement, SET SQLCA and some DECLARE statements do not generate code and thus may appear before the CONNECT statement in the source file. Otherwise, no statements are allowed until a successful CONNECT statement has been executed.

The user ID and password are used for permission checks on all dynamic SQL statements.

For a detailed description of the connection algorithm, see Troubleshooting connections.

Note

For SQL Anywhere, only Syntax 1 is valid with embedded SQL. For UltraLite, both Syntax 1 and Syntax 2 can be used with embedded SQL.

Interactive SQL behavior   If no database or server is specified in the CONNECT statement, Interactive SQL remains connected to the current database, rather than to the default server and database. If a database name is specified without a server name, Interactive SQL attempts to connect to the specified database on the current server. If a server name is specified without a database name, Interactive SQL connects to the default database on the specified server.

For example, if the following batch is executed while connected to a database, the two tables are created in the same database.

CREATE TABLE t1( c1 int );
CONNECT DBA IDENTIFIED BY sql;
CREATE TABLE t2 (c1 int );

No other database statements are allowed until a successful CONNECT statement has been executed.

When Interactive SQL is run in windowed mode, you are prompted for any missing connection parameters.

When Interactive SQL is running in command-prompt mode (-nogui is specified when you start Interactive SQL from a command line) or batch mode, or if you execute CONNECT without an AS clause, an unnamed connection is opened. If there is another unnamed connection already opened, the old one is automatically closed. Otherwise, existing connections are not closed when you run CONNECT.

Multiple connections are managed through the concept of a current connection. After a successful connect statement, the new connection becomes the current one. To switch to a different connection, use the SET CONNECTION statement. The DISCONNECT statement is used to drop connections.

When connecting to Interactive SQL, specifying CONNECT [ USER ] userid is the same as executing a SETUSER WITH OPTION userid statement. See SETUSER statement.

In Interactive SQL, the connection information (including the database name, your user ID, and the database server) appears in the title bar above the SQL Statements pane. If you are not connected to a database, Not Connected appears in the title bar.

Note

Both Syntax 1 and Syntax 2 are valid with Interactive SQL with the exception that Interactive SQL does not support the hostvar argument.

Permissions

None.

Side effects

None.

See also
Standards and compatibility
  • SQL/2003   Syntax 1 is a SQL/foundation feature outside of core SQL. Syntax 2 is a vendor extension.

Examples

The following are examples of CONNECT usage within embedded SQL.

EXEC SQL CONNECT AS :conn_name
USER :userid IDENTIFIED BY :password;
EXEC SQL CONNECT USER "DBA" IDENTIFIED BY "sql";

The following examples assume that the SQL Anywhere sample database has already been started.

Connect to a database from Interactive SQL. Interactive SQL prompts for a user ID and a password.

CONNECT;

Connect to the default database as DBA from Interactive SQL. Interactive SQL prompts for a password.

CONNECT USER "DBA";

Connect to the sample database as user DBA from Interactive SQL.

CONNECT
TO demo11
USER DBA
IDENTIFIED BY sql;

Connect to the sample database using a connect string, from Interactive SQL.

CONNECT
USING 'UID=DBA;PWD=sql;DBN=demo';

Once you connect to the sample database, the database name, your user ID, and the database server name appear in the title bar as: demo (DBA) on demo11.