[TDR Generic Table] [MySQL Protocol Compatibility Interface] COUNT

1. Interface Description

Get the number of qualified records in a specified table.

2. Preparations

Refer to Preparation document, create mysql_table table, and use MySQL Client to connect to TcaplusDB successfully.

3. SQL Examples

At present, TcaplusDB only supports the following three basic COUNT functions.

1. Get the number of records in full table, and do not support filter conditions:

SELECT COUNT(*) FROM mysql_table;

1. Get the number of records of index, and do not support filter conditions:

SELECT COUNT(*) FROM mysql_table WHERE k1=1 AND k2=2;

1. Get the number of records of primarykey. The returned result can only be 0 or 1:

SELECT COUNT(*) FROM mysql_table WHERE k1=1 AND k2=2 AND k3='one';

4. FAQ

For details, see Meaning and Handling of Error Codes.

5. Other Reference Documents

None