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Connect to CrossDB

You need a connection instance to connect to CrossDB, and all operations will use this connection handle.

  • Each thread can use only one connection, and each connection can be used by only one thread.
  • All opened databases are shared among all opened connections, and you can use USE DATABASE db_name command to switch the connection's default database.

Connection Modes

  • Embedded mode (local connections)
  • Server mode (remote connections over TCP/IP)
  • Mixed mode (local and remote connections at the same time)

Connect to Embedded Database

  • Open a connection
xdb_conn_t *pConn = xdb_open (NULL);

Note

User has to use OPEN DATABASE '[path/]db_name' or CREATE DATABASE '[path/]db_name' or USE DATABASE db_name.

  • Open a connection and create a default memory database if not exist
xdb_conn_t *pConn = xdb_open (":memory:");
  • Open a connection and create a on-disk database school if not exist as the default database
//  In current folder
xdb_conn_t *pConn = xdb_open ("school");

// In specified folder
xdb_conn_t *pConn = xdb_open ("/var/crossdb/school");

Connect to CrossDB Server

  • Connect to local host CrossDB Server
xdb_conn_t *pConn = xdb_connect (NULL, NULL, NULL, NULL, 7777);
  • Connect to remote host CrossDB Server
xdb_conn_t *pConn = xdb_connect ("192.168.1.1", NULL, NULL, NULL, 7777);

Set current DB

xdb_conn_t *pConn = xdb_connect ("192.168.1.1", NULL, NULL, "school", 7777);

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