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Found 4378 Articles for MySQL
465 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
135 Views
CASE statement with the WHEN clause is used to work around conditions. Following is the syntax−select *, case when yourCondition then yourStatement when yourCondition then yourStatement . . else yourStatement from yourTableName;Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(20), -> StudentMarks int -> ); Query OK, 0 rows affected (0.77 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 78); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('Robert', 88); Query OK, 1 row affected (0.14 sec) ... Read More
57 Views
To replace duplicate records and avoid any error while inserting, use INSERT ON DUPLICATE KEY UPDATE. Let us first create a table −mysql> create table DemoTable -> ( -> Id int, -> Name varchar(20), -> UNIQUE(Id, Name) -> ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(101, 'Chris') on duplicate key update Id=10001, Name='Robert'; Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(102, 'Mike') on duplicate key update Id=10001, Name='Robert'; Query OK, 1 row affected (0.17 sec) mysql> insert into ... Read More
2K+ Views
Yes, we can turn a column records into a list using the MySQL GROUP_CONCAT(). Let us first create a table −mysql> create table DemoTable -> ( -> ClientId int, -> ClientName varchar(20) -> ); Query OK, 0 rows affected (0.88 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 'Chris'); Query OK, 1 row affected (0.54 sec) mysql> insert into DemoTable values(100, 'Robert'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(100, 'Adam'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(100, 'David'); Query OK, ... Read More
580 Views
To create a temporary table with dates, use the CREATE TEMPORARY TABLE in MySQL. Following is the syntax −Syntaxcreate temporary table yourTableName( yourColumnName datetime );Let us first create a table −mysql> create temporary table DemoTable -> ( -> DueDate datetime -> ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(now()); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable values(curdate()); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable values('2018-01-21'); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More
694 Views
To increase item value for multiple items in a single query, you can use the CASE statement in MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> ProductName varchar(20), -> ProductPrice int -> ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Product-1', 700); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Product-2', 1000); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Product-3', 3000); Query OK, 1 row affected (0.10 sec)Display all records from ... Read More
1K+ Views
For this, you can use GROUP BY HAVING along with the COUNT(*) function. Let us first create a table −mysql> create table DemoTable -> ( -> Value int -> ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable ... Read More
373 Views
It would be good to use IN() instead of multiple OR statements. Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> FirstName varchar(20) -> ); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(FirstName) values('Adam'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable(FirstName) values('David'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(FirstName) values('Mike'); Query OK, 1 ... Read More
1K+ Views
To implement custom sort order in MySQL, you need to use ORDER BY FIELD(). Let us first create a table −mysql> create table DemoTable -> ( -> Designation varchar(100) -> ); Query OK, 0 rows affected (1.65 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Software Engineer'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Associate Software Engineer'); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable values('Software Development Engineer'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Product Manager'); Query OK, 1 row ... Read More
179 Views
To subtract a day in MySQL, use the DATE_SUB() method. Let us first create a table −mysql> create table DemoTable -> ( -> AdmissionDate timestamp -> ); Query OK, 0 rows affected (1.05 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-01-01'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('2018-12-31'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('2017-03-13'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('2019-01-02'); Query OK, 1 row affected (0.08 sec)Display all records from the table using select ... Read More