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MySQL Articles
Page 54 of 355
How to add static value while INSERT INTO with SELECT in a MySQL query?
You can add static value when you use INSERT INTO SELECT MySQL query. Write the value directly in the select statement or you can add with the help of variable which initializes the value.Case 1 − Place the value directly in the INSERT INTO SELECT statement. The syntax is as follows −INSERT INTO yourSecondTableName(yourColumnName1, yourColumnName2, ....N) SELECT yourColumnName1 ,yourColumnName2, .....N, yourStaticValue from yourFirstTableName;Case 2 − Add using variable. The syntax is as follows −SET @yourVariableName − = yourstaticValue; INSERT INTO yourSecondTableName(yourColumnName1, yourColumnName2, ....N) SELECT yourColumnName1 ,yourColumnName2, .....N, @yourVariableName from yourFirstTableName;To understand the above syntax, you need to ...
Read MoreHow to Insert custom date into MySQL timestamp field?
The problem with UNIX_TIMESTAMP() function is that it returns an integer while we want to insert custom date i.e. not any integer part to MySQL date.Do not use UNIX_TIMESTAMP() for your column defined as TIMESTAMP because UNIX_TIMESTAMP() returns an integer.Check the UNIX_TIMESTAMP. The query is as follows −mysql> select UNIX_TIMESTAMP( '2019-01-09 15 −48 −23') AS IntegerValue;The following is the output −+--------------+ | IntegerValue | +--------------+ | 1547029103 | +--------------+ 1 row in set (0.00 sec)Look at the sample output, the UNIX_TIMESTAMP() function returns an integer of corresponding date and time.The syntax is as follows to insert custom date for ...
Read MoreMySQL - SELECT ... WHERE id IN (..) order with particular column?
You can SELECT ….WHERE id IN(..) using field() function to order with any column. The syntax is as follows −SELECT *FROM yourTableName WHERE yourColumnName IN(‘value1’, ’value2’, .......N) ORDER BY FIELD(yourColumnName, value1’, ’value2’, .......N);To understand the above syntax, let us create a table −mysql> create table SelectOrderbyField -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(30), -> Age int, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into SelectOrderbyField(Name, Age) values('John', 23); Query OK, ...
Read MoreMySQL Order By specific strings?
Order by the choice of strings you want, using the FIELD() function. The syntax is as follows −SELECT *FROM yourTableName ORDER BY FIELD(yourColumnName, ’yourValue1’, ’yourValue2’, ’yourValue3’, ....N);To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table OrderByListOfStrings -> ( -> Id int not null auto_increment, -> CarName varchar(20), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into OrderByListOfStrings(CarName) values('Ford'); Query OK, 1 row affected ...
Read MoreHow to update two columns in a MySQL database?
You can update two columns using SET command separated with comma(, ). The syntax is as follows −UPDATE yourTableName SET yourColumnName1 = ’yourValue1’, yourColumnName2 = ’yourValue2’ where yourCondition;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table StudentInformations -> ( -> StudentId int not null auto_increment, -> StudentFirstName varchar(20), -> StudentLastName varchar(20), -> Primary Key(StudentId) -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into StudentInformations(StudentFirstName, StudentLastName) ...
Read MoreGet table column names in alphabetical order in MySQL?
To get the table column names in alphabetical order, you need to use ORDER BY. The syntax is as follows −SELECT anyReferenceName.COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS anyReferenceName WHERE anyReferenceName.TABLE_NAME = ’yourTableName’ ORDER BY anyReferenceName.COLUMN_NAMEFirst, we need to get all the columns and then we need to use ORDER BY. In the above query, we are getting all columns using INFORMATION_SCHEMA.COLUMNS.To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table ColumnsOrder -> ( -> StudentFirstName varchar(20), -> Id int, -> StudentAge int, -> StudentLastName varchar(20) ...
Read MoreFind max and second max salary for a MySQL Employee table?
You can get max and second max salary from an Employee table using LIMIT OFFSET. The syntax is as follows −SELECT yourColumnName1, yourColumnName2, ....N from yourTableName ORDER BY yourColumnName desc limit 2 offset 0;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table EmployeeMaxAndSecondMaxSalary -> ( -> EmployeeId int, -> Employeename varchar(20), -> EmployeeSalary int -> ); Query OK, 0 rows affected (0.88 sec)Insert some records in the table using insert command −mysql> insert into EmployeeMaxAndSecondMaxSalary values(1, 'John', 34566); Query OK, 1 row ...
Read MoreHow to ORDER BY LIKE in MySQL?
To order by like in MySQL, use the case statement. The syntax is as follows −SELECT *FROM yourTableName ORDER BY CASE WHEN yourColumnName like '%yourPatternValue1%' then 1 WHEN yourColumnName like '%yourPatternValue2%' then 2 else 3 end;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table OrderByLikeDemo -> ( -> Id int, -> Name varchar(100) -> ); Query OK, 0 rows affected (1.84 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into OrderByLikeDemo values(100, ...
Read MoreHow to add a NOT NULL column in MySQL?
You can add a not null column at the time of table creation or you can use it for an existing table.Case 1 − Add a not null column at the time of creating a table. The syntax is as followsCREATE TABLE yourTableName ( yourColumnName1 dataType NOT NULL, yourColumnName2 dataType . . . N );The query to create a table is as followsmysql> create table NotNullAtCreationOfTable -> ( -> Id int not null, -> Name varchar(100) -> ); Query OK, 0 rows affected (0.60 sec)In the above table, we ...
Read MoreHow to select sum or 0 if no records exist in MySQL?
You can use aggregate function sum() inside COALESCE(). The below syntax returns the sum of all if the record exists otherwise 0 is returned. The syntax is as follows.select COALESCE(sum(yourColumnName2), 0) AS anyVariableName from yourTableName where yourColumnName1 like '%yourValue%';To understand the above syntax, let us create a table. The query to create a table is as follows.mysql> create table SumDemo -> ( -> Words varchar(100), -> Counter int -> ); Query OK, 0 rows affected (0.93 sec)Insert some records in the table using insert command. The query is as follows.mysql> insert into SumDemo values('Are You There', 10); Query OK, 1 ...
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