Updated on 2022-11-18 GMT+08:00

Character

Name

Description

VARCHAR(n)

Variable-length character string. n indicates the byte length.

CHAR(n)

Fixed-length character string. If the length is insufficient, spaces are added. n indicates the byte length. If the precision n is not specified, the default value 1 is used.

VARBINARY

Variable-length binary data. The value must be prefixed with X, for example, X'65683F'. Currently, a binary character string of a specified length is not supported.

JSON

The value can be a JSON object, a JSON array, a JSON number, a JSON string, true, false or null.

STRING

String compatible with impala. The bottom layer is varchar.

BINARY

Compatible with Hive BINARY. The underlying implementation is VARBINARY.

  • In SQL expressions, simple character expressions and unicodes are supported. A unicode character string uses U& as the fixed prefix. An escape character must be added before Unicode that is represented by a 4-digit value.

  • VARBINARY and BINARY
    -- Creating a VARBINARY or BINARY Table
     create table binary_tb(col1 BINARY);
    
    --Insert data.
     INSERT INTO binary_tb values (X'63683F');
    
    --Query data.
     select * from binary_tb ;  -- 63 68 3f 
  • When two CHARs with different numbers of spaces at the end are compared, the two CHARs are considered equal.
    SELECT CAST('FO' AS CHAR(4)) = CAST('FO     ' AS CHAR(5));
     _col0 
    -------
     true  
    (1 row)