Current File : //usr/share/mysql-test/suite/sys_vars/t/group_concat_max_len_func.test
############## mysql-test\t\group_concat_max_len_func.test ####################
# #
# Variable Name: group_concat_max_len #
# Scope: GLOBAL | SESSION #
# Access Type: Dynamic #
# Data Type: numeric #
# Default Value: 1024 #
# Minimum value: 4 #
# #
# #
# Creation Date: 2008-03-07 #
# Author: Salman Rawala #
# #
# Last modification: #
# 2008-11-14 mleich Fix Bug#40644 main.group_concat_max_len_func random #
# failures #
# + minor improvements #
# #
# Description: Test Cases of Dynamic System Variable group_concat_max_len #
# that checks the functionality of this variable #
# #
# Reference: #
# http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html #
# #
###############################################################################
SET @save = @@global.group_concat_max_len;
--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings
#########################
# Creating new table #
#########################
--echo ## Creating new table t1 ##
CREATE TABLE t1
(
id INT NOT NULL AUTO_INCREMENT,
PRIMARY KEY (id),
rollno INT NOT NULL,
name VARCHAR(30)
);
--echo '#--------------------FN_DYNVARS_034_01-------------------------#'
########################################################################
# Setting initial value of group_concat_max_len, inserting some rows
# & creating 2 new connections
########################################################################
--echo ## Setting initial value of variable to 4 ##
SET @@global.group_concat_max_len = 4;
--echo ## Inserting some rows in table ##
INSERT INTO t1(rollno, name) VALUES(1, 'Record_1');
INSERT INTO t1(rollno, name) VALUES(2, 'Record_2');
INSERT INTO t1(rollno, name) VALUES(1, 'Record_3');
INSERT INTO t1(rollno, name) VALUES(3, 'Record_4');
INSERT INTO t1(rollno, name) VALUES(1, 'Record_5');
INSERT INTO t1(rollno, name) VALUES(3, 'Record_6');
INSERT INTO t1(rollno, name) VALUES(4, 'Record_7');
INSERT INTO t1(rollno, name) VALUES(4, 'Record_8');
# The following "auxiliary" select ensures that all records are on disk
# = result sets got by parallel sessions cannot suffer from effects
# caused by the MyISAM feature "concurrent_inserts".
SELECT * FROM t1 ORDER BY id;
--echo ## Creating two new connections ##
connect (test_con1,localhost,root,,);
connect (test_con2,localhost,root,,);
--echo '#--------------------FN_DYNVARS_034_02-------------------------#'
###############################################################################
# Verifying initial behavior of variable by concatinating values greater than 4
###############################################################################
--echo ## Connecting with test_con1 ##
connection test_con1;
--echo ## Accessing data and using group_concat on column whose value is greater than 4 ##
SELECT id, rollno, GROUP_CONCAT(name) FROM t1 GROUP BY rollno;
--echo ## Changing session value of variable and verifying its behavior, ##
--echo ## warning should come here ##
SET @@session.group_concat_max_len = 10;
SELECT id, rollno, GROUP_CONCAT(name) FROM t1 GROUP BY rollno;
--echo '#--------------------FN_DYNVARS_034_03-------------------------#'
##############################################################################
# Verifying behavior of variable by increasing session value of variable #
##############################################################################
--echo ## Connecting with new connection test_con2 ##
connection test_con2;
--echo ## Verifying initial value of variable. It should be 4 ##
SELECT @@session.group_concat_max_len = 4;
--echo ## Setting session value of variable to 20 and verifying variable is concating ##
--echo ## column's value to 20 or not ##
SET @@session.group_concat_max_len = 20;
--echo ## Verifying value of name column, it should not me more than 20 characters ##
--echo ## Warning should come here ##
SELECT id, rollno, GROUP_CONCAT(name) FROM t1 GROUP BY rollno;
--echo '#--------------------FN_DYNVARS_034_04-------------------------#'
###############################################################################
# Verifying behavior of variable by increasing session value of variable #
# greater than the maximum concat length of name column #
###############################################################################
--echo ## Setting session value of variable to 26. No warning should appear here ##
--echo ## because the value after concatination is less than 30 ##
SET @@session.group_concat_max_len = 26;
--echo ## Verifying value of name column, it should not give warning now ##
SELECT id, rollno, GROUP_CONCAT(name) FROM t1 GROUP BY rollno;
############################################################
# Disconnecting all connection & dropping table #
############################################################
--echo ## Dropping table t1 ##
DROP TABLE t1;
--echo ## Disconnecting both the connection ##
disconnect test_con2;
disconnect test_con1;
connection default;
SET @@global.group_concat_max_len = @save;
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