MySQL Articles

Page 159 of 355

Add an autoincrement column with a custom start value in MySQL

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 1K+ Views

To add a new column to an already created table, use ALTER TABLE and ADD COLUMN. Use AUTO_INCREMENT to set auto increment custom value.Let us first create a table −mysql> create table DemoTable    -> (    -> StudentName varchar(20)    -> ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Adam'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.12 sec)Display all records from the table using ...

Read More

MySQL query error with a table named "order"?

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 515 Views

The order is a reserved word. To still use a reserved word, you need to use backticks around the column name. Let us first create a table −mysql> create table `order`    -> (    -> StudentId int    -> ); Query OK, 0 rows affected (1.78 sec)Insert some records in the table using insert command −mysql> insert into `order` values(101); Query OK, 1 row affected (0.26 sec) mysql> insert into `order` values(210); Query OK, 1 row affected (0.18 sec) mysql> insert into `order` values(190); Query OK, 1 row affected (0.28 sec) mysql> insert into `order` values(180); Query OK, 1 ...

Read More

Show row with zero value after addition in MySQL?

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 190 Views

For this, you can use an aggregate function SUM() along with the condition. Let us first create a table −mysql> create table DemoTable    -> (    -> Status varchar(20)    -> ); Query OK, 0 rows affected (1.22 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('active'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('active'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('active'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable values('active'); Query OK, 1 row affected (0.18 sec)Display all records from the ...

Read More

Find rows with a match in a pipe delimited column with MySQL

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 572 Views

To find a match, use regular expressions in MySQL. Let us first create a table −mysql> create table DemoTable    -> (    -> Value varchar(60)    -> ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('8|56|78|45'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values('9876'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('98|8'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('3|8|9'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('97|94'); Query OK, 1 ...

Read More

MySQL search and replace record from a list of records

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 164 Views

Let us first create a table −mysql> create table DemoTable    -> (    -> ListOfName text    -> ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Carol, Sam, John, David, Bob, Mike, Robert, John, Chris, James, Jace'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------------------------------------------------------------+ | ListOfName                                               ...

Read More

How to extract date from string in MySQL?

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 773 Views

To extract date from the string in MySQL, use SUBSTRING_INDEX(). Let us first create a table −mysql> create table DemoTable    -> (    -> Title text    -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John has got joining date.12/31/2018'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Carol has got joining date.01/11/2019'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('Sam will arrive at.12/03/2050'); Query OK, 1 row affected (0.87 sec)Display all records from the table using select statement ...

Read More

MySQL query to find the number of occurrences from two columns?

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 519 Views

Use MySQL GROUP_BY to find the number of occurrences from two columns. Let us first create a table −mysql> create table DemoTable    -> (    -> Name1 varchar(20),    -> Name2 varchar(20)    -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John', 'Adam'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Chris', 'David'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Robert', 'Mike'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('David', 'Chris'); Query OK, 1 row ...

Read More

Find the difference between dates in the form of months with MySQL

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 2K+ Views

Let us first create a table −mysql> create table DemoTable    -> (    -> Date1 date,    -> Date2 date    -> ); Query OK, 0 rows affected (1.04 sec)Insert some records in the table using insert command &miuns;mysql> insert into DemoTable values('2017-01-10', '2017-12-10'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('2018-12-31', '2015-01-02'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('2020-03-01', '2019-06-15'); Query OK, 1 row affected (0.19 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------------+------------+ | Date1     ...

Read More

How to use ORDER BY field and sort by id in a single MySQL field?

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 719 Views

For this, you can use ORDER BY FIELD. Let us first create a table −mysql> create table DemoTable    -> (    -> Id int,    -> Name varchar(20)    -> ); Query OK, 0 rows affected (1.78 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(101, 'Chris'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable values(201, 'Mike'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(110, 'Adam'); Query OK, 1 row affected (0.52 sec) mysql> insert into DemoTable values(250, 'John'); Query OK, 1 row affected (0.33 sec)Display all ...

Read More

Select distinct values from three columns and display in a single column with MySQL

AmitDiwan
AmitDiwan
Updated on 13-Dec-2019 589 Views

For this, use UNION more than once in a single MySQL query. Let us first create a table −mysql> create table DemoTable    -> (    -> Value1 int,    -> Value2 int,    -> Value3 int    -> ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(20, null, null); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(20, null, null); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(20, null, null); Query OK, 1 row affected (0.12 sec) mysql> insert into ...

Read More
Showing 1581–1590 of 3,547 articles
« Prev 1 157 158 159 160 161 355 Next »
Advertisements