Overview

This provides an example of running esql in multi thread.

When running esql in multi thread, you must add THREADS=YES option to the esql precompile command for compilation. Also, in the source code, set EXEC SQL ENABLE THREADS; and EXEC SQL CONTEXT USE DEFAULT;.

Method

Sample Code

#include <stdio.h>
#include <string.h>

void esql_error(int line_no, int err_no, char *file)
{
    printf("esql test esql_error at %d : %d in %s\n", line_no, err_no, file);
}

void
main(void)
{
    char *uid = "tibero";
    char *pwd = "tmax";

    int balance = 0;

    sql_context ctx1;
    sql_context ctx2;

    printf("***** thread context test start *****\n\n");

    EXEC SQL WHENEVER SQLERROR DO esql_error(__LINE__, sqlca.sqlcode, __FILE__);

    EXEC SQL ENABLE THREADS;

    EXEC SQL CONTEXT USE DEFAULT;

    EXEC SQL CONNECT :uid IDENTIFIED BY :pwd;

    EXEC SQL WHENEVER SQLERROR continue;

    EXEC SQL DROP TABLE ACCOUNT;

    EXEC SQL CREATE TABLE ACCOUNT (
        ACCOUNT_ID      CHAR(14),
        BRANCH_CD       CHAR(4),
        CUSTOMER_ID     CHAR(13),
        ACCOUNT_TYPE    CHAR(4),
        BALANCE         NUMBER(15, 5),
        CREATE_DATE     DATE,
        EXPIRY_DATE     DATE
    );

    EXEC SQL WHENEVER SQLERROR DO esql_error(__LINE__, sqlca.sqlcode, __FILE__);

    EXEC SQL INSERT INTO account
        VALUES ('ACCOUNT_ID_001', 'B003', 'CUSTOMER_ID_0',
                'A002', 500000, '2003-10-5', '2005-10-5');
    EXEC SQL INSERT INTO account
        VALUES ('ACCOUNT_ID_002', 'B003', 'CUSTOMER_ID_1',
                'A001', 10000, '2003-12-25', '2010-12-25');
    EXEC SQL INSERT INTO account
        VALUES ('ACCOUNT_ID_003', 'B001', 'CUSTOMER_ID_2',
                'A003', 50000000, '1998-9-1', '2005-9-1');

    EXEC SQL COMMIT WORK;

    EXEC SQL CONTEXT ALLOCATE :ctx1;

    EXEC SQL CONTEXT ALLOCATE :ctx2;

    EXEC SQL CONTEXT USE :ctx1;

    EXEC SQL CONNECT :uid IDENTIFIED BY :pwd;

    EXEC SQL SELECT BALANCE INTO :balance FROM ACCOUNT
        WHERE ACCOUNT_ID = 'ACCOUNT_ID_001';

    if (balance != 500000)
        printf("expected : 500000, real : %d\n", balance);

    EXEC SQL CONTEXT USE :ctx2;

    EXEC SQL CONNECT :uid IDENTIFIED BY :pwd;

    EXEC SQL SELECT BALANCE INTO :balance FROM ACCOUNT
        WHERE ACCOUNT_ID = 'ACCOUNT_ID_002';

    if (balance != 10000)
        printf("expected : 10000, real : %d\n", balance);

    EXEC SQL CONTEXT FREE :ctx1;

    EXEC SQL CONTEXT FREE :ctx2;

    EXEC SQL CONTEXT USE DEFAULT;

    EXEC SQL SELECT BALANCE INTO :balance FROM ACCOUNT
        WHERE ACCOUNT_ID = 'ACCOUNT_ID_002';

    if (balance != 10000)
        printf("expected : 10000, real : %d\n", balance);

    printf("***** thread context test end *****\n");
}

Execution

[tibero7_kb]tibero@ENT-ROCKY8:/tibero/user/kyobin_jeon/test> tbpc THREADS=YES sample1.tbc

tbESQL Precompiler 7

TmaxTibero Corporation Copyright (c) 2020-. All rights reserved.


sample1.tbc is precompiled successfully!


[tibero7_kb]tibero@ENT-ROCKY8:/tibero/user/kyobin_jeon/test> gcc -o sample1 sample1.c  -L$TB_HOME/client/lib -ltbertl -l tbcli -lpthread -lm -I$TB_HOME/client/include

[tibero7_kb]tibero@ENT-ROCKY8:/tibero/user/kyobin_jeon/test> ls -lrt
total 132
drwxr-xr-x. 10 tibero dba   113 Nov  6 16:05 tibero7
-rw-r--r--.  1 tibero dba   669 Dec 17 08:42 test.tbc
-rw-r--r--.  1 tibero dba 16247 Dec 17 08:44 test.c
-rwxr-xr-x.  1 tibero dba 22440 Dec 17 08:44 test
-rw-r--r--.  1 tibero dba  2437 Dec 17 08:53 sample1.tbc
-rw-r--r--.  1 tibero dba 50457 Dec 17 08:54 sample1.c
-rwxr-xr-x.  1 tibero dba 30672 Dec 17 08:55 sample1

[tibero7_kb]tibero@ENT-ROCKY8:/tibero/user/kyobin_jeon/test> ./sample1
***** thread context test start *****

***** thread context test end *****