MySQL Articles

Page 154 of 355

Get the size of selected rows in MySQL

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 2K+ Views

To get the size of selected rows, use CHAR_LENGTH(). Let us first create a table −mysql> create table DemoTable1612    -> (    -> FirstName varchar(20),    -> LastName varchar(20)    -> ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1612 values('David', 'Brown'); Query OK, 1 row affected (0.75 sec) mysql> insert into DemoTable1612 values('John', 'Smith'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable1612 values('Bob', 'Taylor'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select * from DemoTable1612;This ...

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Combine multiple text records to one in MySQL

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 304 Views

To combine multiple text records, use GROUP_CONCAT(). Let us first create a table −mysql> create table DemoTable1611    -> (    -> Value text    -> ); Query OK, 0 rows affected (0.86 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1611 values('John'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1611 values('is'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1611 values('learning'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1611 values('Java'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1611 values('with'); Query OK, 1 row affected ...

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Custom sorting using two different columns in MySQL?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 265 Views

For this, use ORDER BY clause along with CASE statement. Let us first create a table −mysql> create table DemoTable1610    -> (    -> Marks int,    -> Name varchar(20)    -> ) ; Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1610 values(85, 'John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1610 values(78, 'Carol'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1610 values(78, 'John'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable1610 values(85, 'Carol'); Query OK, 1 row affected ...

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How to correctly use DELIMITER in a MySQL stored procedure?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 398 Views

The correct way is as follows −DELIMITER // CREATE PROCEDURE yourStoredProcedureName() BEGIN  IF  yourCondition then      yourStatement1 ; else     yourStatement2 ; END IF ; END // DELIMITER ;Let us now see an example and create a stored procedure −mysql> DELIMITER // mysql> CREATE PROCEDURE delimiter_demo()    -> BEGIN    -> IF 1 THEN    -> SELECT "If condition will always true";    -> else    -> select "No" ;    -> END IF ;    -> END    -> // Query OK, 0 rows affected (0.17 sec) mysql> DELIMITER ;Now you can call the ...

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Select the minimum value from the maximum values of two tables with a single MySQLnquery?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 226 Views

For this, you can use UNION in MySQL. Let us first create a table −mysql> create table DemoTable1    -> (    -> Value int    -> )    -> ; Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(60); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1 values(78); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1 values(57); Query OK, 1 row affected (0.08 sec)Display all records from the table using select statement −mysql> select * from DemoTable1; This will produce the following ...

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What are the minimum MySQL user privileges to allow optimize and repair?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 443 Views

The select and insert statements are the minimum required MySQL user privileges to allow optimize and repair.You can use below syntax to give insert and select privileges to the user −grant insert, select on yourDatabaseName.* to 'yourUserName'@'localhost';At first, here is the query to create a user −mysql> create user 'Emma'@'localhost' identified by 'Emma123'; Query OK, 0 rows affected (0.26 sec)Here is the query to give grants for the above user −mysql> grant insert, select on web.* to 'Emma'@'localhost'; Query OK, 0 rows affected (0.21 sec)Here is the query to display all grants of the above user −mysql> show grants for ...

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Query for implementing MySQL LIKE as MySQL IN?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 233 Views

To implement a query like MySQL IN(), you need to use COUNT(), IF() along with LIKE operator. Let us first create a table −mysql> create table DemoTable    -> (    -> Subject varchar(80)    -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('MySQLMongoDB'); Query OK, 1 row affected (0.86 sec) mysql> insert into DemoTable values('MySQL'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('JavaMySQL'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('MongoDB'); Query OK, 1 row affected (0.20 sec) ...

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Fetch maximum value from multiple columns with null and non-null values?

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 502 Views

For this, you can use COALESCE(). For the maximum value, use GREATEST() in MySQL. Let us first create a table −mysql> create table DemoTable    -> (    -> Value1 int,    -> Value2 int,    -> Value3 int    -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(NULL, 80, 76); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(NULL, NULL, 100); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(56, NULL, 45); Query OK, 1 row affected (0.20 sec) mysql> ...

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Format MySQL records (price values) after multiplying them

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 228 Views

To format records, use FORMAT(). Let us first create a table −mysql> create table DemoTable    -> (    -> Price decimal(10, 4),    -> Rate decimal(10, 4)    -> ); Query OK, 0 rows affected (0.96 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1000, 10.2); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(2000, 20.4); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(100, 5); Query OK, 1 row affected (0.16 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the ...

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MySQL LIKE command doesn't work with strings containing dots to display records beginning with a specific number

AmitDiwan
AmitDiwan
Updated on 17-Dec-2019 550 Views

To work with strings containing dots, and display records beginning with a specific number, you need to use REGEXP. Let us first create a table −mysql> create table DemoTable    -> (    -> GameReleaseVersion varchar(20)    -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('19.6'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('18.4'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('17.6'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('19.5'); Query OK, 1 row affected ...

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