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MySQLi Articles
Page 275 of 341
MySQL: Testing connection with query?
Use any predefined function with select query or you can print some words with the select query in order to test connection with query.The syntax is as follows.SELECT yourValue;The select query with predefined function is as follows.The syntax is as follows.SELECT anyPredefinedFunctionName();Now you can implement the above syntax in order to test connection with query.Case 1 -The query is as follows.mysql> select "This is MySQL" as Display;The following is the output.+---------------+ | Display | +---------------+ | This is MySQL | +---------------+ 1 row in set (0.00 sec)Case 2 -The query is as follows.mysql> select ...
Read MoreGet the returned record set order in MySQL IN clause?
For returned record set order, you need to use FIND_IN_SET() function. For an example, let us create a table.mysql> create table returnRecordSetOrderDemo -> ( -> Id int, -> Name varchar(20) -> ); Query OK, 0 rows affected (1.01 sec)Insert some records in the table using insert command.The query is as follows.mysql> insert into returnRecordSetOrderDemo values(100, 'John'); Query OK, 1 row affected (0.13 sec) mysql> insert into returnRecordSetOrderDemo values(130, 'Carol'); Query OK, 1 row affected (0.13 sec) mysql> insert into returnRecordSetOrderDemo values(103, 'Bob'); Query OK, 1 row affected (0.17 sec) mysql> insert into returnRecordSetOrderDemo values(134, 'Sam'); Query OK, ...
Read MoreHow do I delete blank rows in MySQL?
Use the delete command to delete blank rows in MySQL.The syntax is as followsdelete from yourTableName where yourColumnName=' ' OR yourColumnName IS NULL;The above syntax will delete blank rows as well as NULL row.To understand the concept, let us create a table.The query to create a table is as followsmysql> create table deleteRowDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20) -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into deleteRowDemo(StudentName) values('John'); Query OK, 1 row affected ...
Read MoreMySQL server version for the right syntax to use near 'OPTION SQL_SELECT_LIMIT=10'?
You can use SET command, but SET OPTIOn deprecated. Therefore, use SET SQL_SELECT_LIMIT.The syntax is as follows −SET SQL_SELECT_LIMIT=yourIntegerValue;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table MySQLSelectDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY -> ); Query OK, 0 rows affected (0.99 sec)Insert some records in the table using insert command. The query is as follows −mysql> INSERT INTO MySQLSelectDemo VALUES(), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), ...
Read MoreIs it possible to have View and table with the same name in MySQL?
No, you cannot give the same name for view and table in MySQL.Let us first create a demo table −mysql> create table view_Table_Demo -> ( -> Id int, -> Name varchar(20) -> ); Query OK, 0 rows affected (0.80 sec)Now you can insert some records in the table using insert command. The query is as follows −mysql> insert into view_Table_Demo values(100, 'Larry'); Query OK, 1 row affected (0.17 sec) mysql> insert into view_Table_Demo values(101, 'Mike'); Query OK, 1 row affected (0.20 sec) mysql> insert into view_Table_Demo values(102, 'Sam'); Query OK, 1 row affected (0.14 sec)Display all ...
Read MoreDoes MySQL eliminate common subexpressions between SELECT and HAVING/GROUP BY clause? How to test it?
To test, use the sleep() function.Case 1 −The syntax is as follows −SELECT yourColumnName+sleep(yourIntegerValue) FROM yourTableName GROUP BY yourColumnName+sleep(yourIntegerValue);;Case 2 − You can use another syntax which is as follows −SELECT yourColumnName+sleep(yourIntegerValue) As anyAliasName FROM yourTableName GROUP BY yourAliasName;To understand the above syntaxes, let us create a table. The query to create a table is as follows −mysql> create table sleepDemo -> ( -> value int -> ); Query OK, 0 rows affected (1.25 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into sleepDemo values(40); Query OK, 1 row ...
Read MoreMySQL select dates in 30-day range?
To select dates in 30-day range, you can use arithmetic operation - with interval.The syntax is as follows −select *from yourTableName where yourDateColumnName > NOW() - INTERVAL 30 DAY and yourDateColumnName < NOW() + INTERVAL 30 DAY;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table selectDatesDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ArrivalDate datetime -> ); Query OK, 0 rows affected (0.77 sec)Now you can insert some records in the table using insert command. The query is as ...
Read MoreCount top 10 most occurring values in a column in MySQL?
To count the top 10 most occurring values in a column in MySQL, The syntax is as follows −SELECT yourColumnName, count(*) FROM yourTableName GROUP BY yourColumnName ORDER BY count(*) DESC LIMIT 10;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table countTop10Demo -> ( -> Value int -> ); Query OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into countTop10Demo values(10); Query OK, 1 row affected (0.12 sec) ...
Read MoreHow to remove hyphens using MySQL UPDATE?
To remove hyphens using MySQL update, you can use replace() function. The syntax is as follows −update yourTableName set yourColumnName=replace(yourColumnName, '-', '' );To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table removeHyphensDemo -> ( -> userId varchar(100) -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into removeHyphensDemo values('John-123-456'); Query OK, 1 row affected (0.22 sec) mysql> insert into removeHyphensDemo values('Carol-9999-7777-66555'); Query OK, 1 row affected (0.19 sec) ...
Read MoreMySQL select order by acts like a string (not a number)?
You can use the following syntax if your column has varchar data type −select yourColumnName FROM yourTableName ORDER BY yourColumnName +0 DESC;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table selectOrderdemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(100), -> RankNumber varchar(100) -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into selectOrderdemo(Name, RankNumber) values('Larry', -100); Query OK, 1 row affected (0.23 ...
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