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Articles by AmitDiwan
Page 746 of 840
Get boolean result whether table exists or not using CASE WHEN in MySQL
For this, you can use INFORMATION_SCHEMA.TABLES and find the table you want to search. Let us first create a table −mysql> create table DemoTable -> ( -> Id int, -> Name varchar(20) -> ); Query OK, 0 rows affected (1.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(101, 'Chris'); Query OK, 1 row affected (0.71 sec) mysql> insert into DemoTable values(102, 'David'); Query OK, 1 row affected (0.20 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------+-------+ | Id ...
Read MoreConcatenate columns from different tables in MySQL
You can use CONCAT(). Let us first create a table −mysql> create table DemoTable1 -> ( -> FirstName varchar(20) -> ); Query OK, 0 rows affected (0.90 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values('Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1 values('David'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce the following output −+-----------+ | FirstName | +-----------+ | Chris | | David | +-----------+ 2 rows in set ...
Read MoreHow to select a field corresponding to the field in which MAX() exists?
For this, you can use sub query along with aggregate function MAX(). Let us first create a table −mysql> create table DemoTable -> ( -> ProductId int, -> ProductAmount int -> ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1001, 7895); Query OK, 1 row affected (0.32 sec) mysql> insert into DemoTable values(1003, 8903); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(1010, 7690); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(2010, 8450); Query OK, 1 row ...
Read MoreAdd an autoincrement column with a custom start value in MySQL
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 MoreMySQL query error with a table named "order"?
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 MoreShow row with zero value after addition in MySQL?
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 MoreFind rows with a match in a pipe delimited column with MySQL
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 MoreMySQL search and replace record from a list of records
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 MoreHow to extract date from string in MySQL?
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 MoreMySQL query to find the number of occurrences from two columns?
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 ...
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