AmitDiwan has Published 11365 Articles

How to generate 5 random numbers in MySQL stored procedure?

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:29:04

248 Views

To generate random numbers, use the ORDER BY RAND() function in MySQL. Let us first create a table −mysql> create table DemoTable (Value int); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(89); Query OK, 1 row affected (0.19 ... Read More

How to set different auto-increment ids for two tables with a user-defined variable?

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:25:48

205 Views

For this, you can use LAST_INSERT_ID(). Let us first create a table. Here, we have set the auto_increment id to StudentId column −mysql> create table DemoTable1 (StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert ... Read More

Is MySQL's SLEEP() function a busy-wait? How to implement it?

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:22:45

233 Views

No, MySQL sleep function is not busy-wait. Let us first create a table and implement the SLEEP() function −mysql> create table DemoTable(FirstName varchar(100)); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.15 sec) ... Read More

MySQL order by field using CASE Statement

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:17:21

691 Views

To order by field, use CASE statement. Let us first create a table −mysql> create table DemoTable(StudentId varchar(100)); Query OK, 0 rows affected (1.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('STU-980'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable values('STU-1029'); ... Read More

Getting count of two different sets of rows in a table and then dividing them in MySQL

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:13:36

732 Views

For this, use count(*) and the divide the count of two different sets of rows. Let us first create a table −mysql> create table DemoTable(isMarried tinyint(1)); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1); Query OK, 1 row ... Read More

Copy all rows of a table to another table in MySQL?

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:05:17

631 Views

To copy all rows of a table to another table, use the below syntax −insert into yourTableName2(yourColumnName1, ...N) select yourColumnName1, ..N from yourTableName1;Let us first create a table −mysql> create table DemoTable1(FirstName varchar(100)); Query OK, 0 rows affected (1.11 sec)Insert some records in the table using insert command −mysql> insert ... Read More

MySQL query to sum the values of similar columns from two different tables for a particular ID

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 11:02:31

365 Views

Let’s say we have two tables and both of them have two columns PlayerId and PlayerScore. We need to add the PlayerScore from both these tables, but only for a particular PlayerId.For this, you can use UNION. Let us first create a table −mysql> create table DemoTable1(PlayerId int, PlayerScore int); ... Read More

Filter query by current date in MySQL

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 10:57:51

1K+ Views

Let us first create a table −mysql> create table DemoTable(DueDate datetime); Query OK, 0 rows affected (0.94 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-07-10 04:20:00'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('2019-07-10 05:10:40'); Query OK, 1 row affected ... Read More

Using CREATE TABLE AS statement with UNION of two tables in MySQL

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 10:54:03

2K+ Views

For this, you can use UNION. Let us first create a table −mysql> create table DemoTable1(FirstName varchar(1000)); Query OK, 0 rows affected (1.22 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values('John'); Query OK, 1 row affected (0.20 sec)Display all records from the table using ... Read More

How to check an empty table already in a MySQL database?

AmitDiwan

AmitDiwan

Updated on 22-Aug-2019 10:48:25

1K+ Views

To check an empty table is in a database, you need to extract some records from the table. If the table is not empty then the table records would be returned.Let us first create a table −mysql> create table DemoTable(Id int, Name varchar(100), Age int); Query OK, 0 rows affected ... Read More

Advertisements