Help Center/ GaussDB/ Developer Guide(Centralized_V2.0-8.x)/ Application Development Guide/ ECPG-based Development/ Running SQL Commands/ Embedded SQL Commands/ TYPE
Updated on 2025-05-29 GMT+08:00
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TYPE

Function

Defines a new data type. This command is identified only when ecpg is run with the -c option.

Syntax

TYPE type_name IS ctype

Parameters

type_name

Data type name.

ctype

C type description.

Examples

EXEC SQL TYPE customer IS
    struct
    {
        varchar name[50];
        int     phone;
    };

EXEC SQL TYPE cust_ind IS
    struct ind
    {
        short   name_ind;
        short   phone_ind;
    };

EXEC SQL TYPE c IS char reference;
EXEC SQL TYPE ind IS union { int integer; short smallint; };
EXEC SQL TYPE intarray IS int[AMOUNT];
EXEC SQL TYPE str IS varchar[BUFFERSIZ];
EXEC SQL TYPE string IS char[11];
Example of using EXEC SQL TYPE (note that the -c parameter needs to be added in the ecpg preprocessing phase when the following example is used): 
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

EXEC SQL WHENEVER SQLERROR SQLPRINT;  
EXEC SQL TYPE tt IS 
    struct 
    { 
        varchar v[256]; 
        int     i; 
    };  
EXEC SQL TYPE tt_ind IS 
    struct ind { 
        short   v_ind; 
        short   i_ind; 
    };  

int main(void) 
{ 
EXEC SQL BEGIN DECLARE SECTION; 
    tt t; 
    tt_ind t_ind; 
EXEC SQL END DECLARE SECTION; 
     EXEC SQL CONNECT TO testdb AS con1; 
     EXEC SQL SELECT current_database(), 256 INTO :t:t_ind LIMIT 1; 

     printf("t.v = %s\n", t.v.arr); 
     printf("t.i = %d\n", t.i); 

     printf("t_ind.v_ind = %d\n", t_ind.v_ind); 
     printf("t_ind.i_ind = %d\n", t_ind.i_ind); 

     EXEC SQL DISCONNECT con1; 

     return 0; 
}
The output of this example is as follows. 
t.v = testdb 
t.i = 256 
t_ind.v_ind = 0 
t_ind.i_ind = 0
Parent topic: Embedded SQL Commands