MySQL Articles

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How do I force the column alias to be of specific data type in MySQL?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 309 Views

For this, you can use CASE statement. Let us first create a table −mysql> create table DemoTable1505    -> (    -> Value integer unsigned,    -> Status tinyint(1)    -> ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1505 values(20, 0); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1505 values(45, 1); Query OK, 1 row affected (0.08 sec)Display all records from the table using select statement −mysql> select * from DemoTable1505;This will produce the following output −+-------+--------+ | Value | Status | +-------+--------+ |   ...

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Swap a specific column value in MySQL

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 310 Views

Let us first create a table table −mysql> create table DemoTable1504    -> (    -> Id int,    -> FirstName varchar(20)    -> ); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1504 values(101, 'Chris'); Query OK, 1 row affected (0.63 sec) mysql> insert into DemoTable1504 values(102, 'Bob'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable1504 values(103, 'David'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1504 values(104, 'Mike'); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement ...

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Passing NULL to MySQL for auto increment?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 921 Views

Yes, we can pass NULL as in the below syntax −insert into yourTableName values(NULL, yourValue1, yourValue2, ...N);Let us first create a table −mysql> create table DemoTable1503    -> (    -> ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> ClientName varchar(20),    -> ClientAge int    -> ); Query OK, 0 rows affected (0.45 sec)Insert some records in the table using insert command. Since we have set NOT NULL above, it won’t affect auto_increment −mysql> insert into DemoTable1503 values(NULL, 'Chris', 25); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1503 values(NULL, 'David', 28); Query OK, 1 row ...

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MySQL query for sorting on a columns partial value like number in "John_120

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 183 Views

For this, you can use SUBSTRING_INDEX() along with ORDER BY. Let us first create a table −mysql> create table DemoTable1502    -> (    -> StudentId varchar(40)    -> ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1502 values('John_120'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1502 values('John_201'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1502 values('Mike_178'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable1502 values('Bob_198'); Query OK, 1 row affected (0.36 sec)Display all records from the table using select ...

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MySQL query to select multiple rows effectively?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 3K+ Views

You need to use index to select multiple rows effectively. Let us first create a table −mysql> create table DemoTable1501    -> (    -> Id int NOT NULL PRIMARY KEY,    -> URL text    -> ); Query OK, 0 rows affected (0.62 sec)Here is the query to create index −mysql> create index id_index on DemoTable1501(Id); Query OK, 0 rows affected (0.23 sec) Records: 0  Duplicates: 0  Warnings: 0Insert some records in the table using insert command −mysql> insert into DemoTable1501 values(101, 'www.facebook.com'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1501 values(110, 'www.google.com'); Query OK, 1 ...

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Duplicate a MySQL Database without using mysqldump?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 834 Views

To duplicate a MySQL database, the syntax is as follows −create table yourdatabaseName1.yourTableName1 select * from yourdatabaseName2.yourTableName2;Let us first create a table −mysql> use sample; Database changed mysql> create table DemoTable101    -> (    -> Id int,    -> Name varchar(20)    -> ); Query OK, 0 rows affected (1.45 sec)Insert some records in the table using insert command−mysql> insert into DemoTable101 values(101, 'Sam'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable101 values(102, 'Bob'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable101 values(103, 'David'); Query OK, 1 row affected (0.11 sec)Display all records ...

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How to use MySQL LIKE query to search a column value with % in it?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 959 Views

To search a column value with %, the syntax is as follows −select * from yourTableName  where yourColumnName LIKE '\%%';Let us first create a table −mysql> create table DemoTable1497    -> (    -> Name varchar(20)    -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert −mysql> insert into DemoTable1497 values('%JohnSmith'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1497 values('DavidMiller'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1497 values('CarolTaylor%'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1497 values('%DavidMiller'); Query OK, 1 row affected (0.12 ...

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MySQL query to group results by date and display the count of duplicate values?

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 614 Views

Let us first create a table −mysql> create table DemoTable1496    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> PassengerCode varchar(20),    -> ArrivalDate datetime    -> ); Query OK, 0 rows affected (0.85 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1496(PassengerCode, ArrivalDate) values('202', '2013-03-12 10:12:34'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable1496(PassengerCode, ArrivalDate) values('202_John', '2013-03-12 11:00:00'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1496(PassengerCode, ArrivalDate) values('204', '2013-03-12 10:12:34'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1496(PassengerCode, ArrivalDate) values('208', '2013-03-14 ...

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Get two days data (today and yesterday) from a MySQL table with timestamp values

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 372 Views

Let us first create a table −mysql> create table DemoTable1495    -> (    -> ShippingDate bigint    -> ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1495 values(1570127400); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1495 values(1570213800); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1495 values(1570645800); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1495 values(1570300200); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select * from DemoTable1495;This will produce the following ...

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Fix MySQL ERROR 1064 (42000) check the manual that corresponds to your MySQL server version for the right syntax to use near ')'

AmitDiwan
AmitDiwan
Updated on 11-Dec-2019 4K+ Views

This error may occur if you have used an incorrect syntax. Let’s say the following is the create table statement −mysql> create table DemoTable1492    -> (    -> timestamp TIMESTAMP,    -> event int,    -> ); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 5You need to remove extra comma above after the event column to fix. Let us first create a −mysql> create table DemoTable1492    -> (    -> timestamp TIMESTAMP,   ...

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