Found 6705 Articles for Database

MySQL query to order by NULL values

AmitDiwan
Updated on 21-Aug-2019 12:10:19

199 Views

Let us first create a table −mysql> create table DemoTable707 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentFirstName varchar(100),    StudentMarks int ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable707(StudentFirstName, StudentMarks) values('John', 45); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable707(StudentFirstName, StudentMarks) values(NULL, 65); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable707(StudentFirstName, StudentMarks) values('Chris', 78); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable707(StudentFirstName, StudentMarks) values(NULL, 89); Query OK, 1 row affected (0.19 sec) mysql> insert into ... Read More

MySQL query to get the current date records wherein one of the columns displays current date

AmitDiwan
Updated on 21-Aug-2019 12:07:06

228 Views

To achieve this, following is the syntax wherein we have used DATE(NOW()) −select *from yourTableName where DATE(yourColumnName)=DATE(NOW());Let us first create a table −mysql> create table DemoTable706 (    UserId varchar(100),    UserName varchar(100),    UserSignupDate datetime ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable706 values('John1@gmail.com', 'John', '2019-01-31 12:45:22'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable706 values('Chris123@gmail.com', 'Chris', '2019-07-22 10:05:02'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable706 values('12Robert@gmail.com', 'Robert', '2019-06-22 11:25:22'); Query OK, 1 row affected (0.22 sec) mysql> insert into ... Read More

MySQL query to retrieve current date from a list of dates

AmitDiwan
Updated on 21-Aug-2019 12:05:32

259 Views

Let’s say the current date is −2019-07-22Let us first create a table −mysql> create table DemoTable705 (ShippingDate datetime); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command −mysql> insert into DemoTable705 values('2019-01-21 23:59:00'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable705 values('2019-07-22 00:00:30'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable705 values('2019-07-21 12:01:30'); Query OK, 1 row affected (0.44 sec)Display all records from the table using select statement −mysql> select *from DemoTable705;This will produce the following output -+---------------------+ | ShippingDate | ... Read More

Get count of how many times a string appears in a MySQL column?

AmitDiwan
Updated on 21-Aug-2019 12:04:15

361 Views

Let us first create a table −mysql> create table DemoTable704 (SubjectName text); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable704 values('Introduction to MySQL'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable704 values('Introduction to MongoDB'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable704 values('Introduction to MySQL'); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable704 values('Introduction to Java'); Query OK, 1 row affected (0.39 sec) mysql> insert into DemoTable704 values('Introduction to MongoDB'); Query OK, 1 row affected (0.14 sec) mysql> insert into ... Read More

Return 0 in a new column when record is NULL in MySQL?

AmitDiwan
Updated on 21-Aug-2019 12:03:03

222 Views

For this, you can use CASE statement. Let us first create a table −mysql> create table DemoTable703 (Price int); Query OK, 0 rows affected (0.46 sec)Insert some records in the table using insert command −mysql> insert into DemoTable703 values(102); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable703 values(null); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable703 values(0); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable703 values(500); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable703 values(100); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable703 values(null); Query ... Read More

Error occurs when table name “references” is set while creating a table

AmitDiwan
Updated on 21-Aug-2019 11:59:28

156 Views

You cannot give table name references because it is a reserved keyword. Wrap it using backticks, for example, `references`.Let us first create a table −mysql> create table `references`(Subject text); Query OK, 0 rows affected (0.44 sec)Insert some records in the table using insert command −mysql> insert into `references` values('Introduction To MySQL'); Query OK, 1 row affected (0.28 sec) mysql> insert into `references` values('Introduction To MongoDB'); Query OK, 1 row affected (0.15 sec) mysql> insert into `references` values('Introduction To Spring and Hibernate'); Query OK, 1 row affected (0.13 sec) mysql> insert into `references` values('Introduction To Java'); Query OK, 1 row affected ... Read More

Update only the int in MySQL Field

AmitDiwan
Updated on 21-Aug-2019 11:58:23

103 Views

Let us first create a table −mysql> create table DemoTable702 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(100),    StudentScore int ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable702(StudentName, StudentScore) values('Chris', 56); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable702(StudentName, StudentScore) values('Robert', 21); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable702(StudentName, StudentScore) values('Mike', 89); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable702(StudentName, StudentScore) values('David', 99); Query OK, 1 row affected (0.20 sec)Display all records from ... Read More

Update the date and time values while inserting them in MySQL

AmitDiwan
Updated on 21-Aug-2019 11:55:41

151 Views

Here, we will see an example wherein we are inserting datetime and updating them while using INSERT query.Let us first create a table −mysql> create table DemoTable816 (DueDate datetime); Query OK, 0 rows affected (0.45 sec)Insert some records in the table using insert command. Here is the query to add (minutes / hours / days / months / years) to date when performing INSERT −mysql> insert into DemoTable816 values(date_add(now(), interval 3 minute)); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable816 values(date_add('2018-01-21 00:00:00', interval 3 Hour)); Query OK, 1 row affected (0.52 sec) mysql> insert into DemoTable816 values(date_add('2016-11-11 ... Read More

Copy from one column to another (different tables same database) in MySQL?

AmitDiwan
Updated on 21-Aug-2019 11:49:55

6K+ Views

To copy from one column to another, you can use INSERT INTO SELECT statement.Let us first create a table −mysql> create table DemoTable1 (PlayerScore int); Query OK, 0 rows affected (0.46 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(98); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable1 values(81); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1 values(76); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1 values(88); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This ... Read More

MySQL query to set my auto increment column ( id ) to zero or reset the value of auto increment field?

AmitDiwan
Updated on 21-Aug-2019 11:48:17

3K+ Views

Use ALTER table to set the auto_increment column to 0 or reset with another valueALTER TABLE yourTableName AUTO_INCREMENT=0;The above syntax will begin from 1.Let us first create a table −mysql> create table DemoTable698 (    ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY ) auto_increment=109; Query OK, 0 rows affected (0.88 sec)Here is the query to reset the auto_increment value to 0 −mysql> alter table DemoTable698 AUTO_INCREMENT=0; Query OK, 0 rows affected (0.21 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command. Here, we haven’t inserted anything since we want to display auto increment value ... Read More

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