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MySQL Articles
Page 307 of 355
Apply MySQL query to each table in a database?
To apply MySQL query to each table in a database, you can use INFORMATION_SCHEMA.TABLES. Following is the syntax −SELECT SUM(TABLE_ROWS) AS anyAliasName FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=yourDatabaseName;Let us implement the above syntax to query each table in a database.mysql> SELECT SUM(TABLE_ROWS) AS Total FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA= DATABASE();This will produce the Following output −+-------+ | Total | +-------+ | 1666 | +-------+ 1 row in set (0.01 sec)
Read MoreGet today's date in (YYYY-MM-DD) format in MySQL?
To get today’s date in (YYYY-MM-DD) format in MySQL, you can use CURDATE().Following is the query to get the current date:mysql> SELECT CURDATE();This will produce the following output:+------------+ | CURDATE() | +------------+ | 2019-04-09 | +------------+ 1 row in set (0.00 sec)You can also use NOW() for this. Following is the query:mysql> SELECT DATE(NOW());This will produce the following output+-------------+ | DATE(NOW()) | +-------------+ | 2019-04-09 | +-------------+ 1 row in set (0.00 sec)
Read MoreMySQL query to get substrings (only the last three characters) from strings?
For this, you can use SUBSTR() method. 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 (1.31 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('Carol'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable(FirstName) values('Robert'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('Chris'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(FirstName) values('David'); ...
Read MoreCan we use stored procedure to insert records into two tables at once in MySQL?
Yes, you can use stored procedure to insert into two tables in a single query. Let us first create a table −mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentFirstName varchar(20) ); Query OK, 0 rows affected (0.56 sec)Here is the query to create second table −mysql> create table DemoTable2 ( ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ClientName varchar(20), ClientAge int ); Query OK, 0 rows affected (0.76 sec)Following is the query to create stored procedure to insert into two tables created above −mysql> DELIMITER // mysql> CREATE PROCEDURE ...
Read MoreHow to compare DateTime Column with only Date not time in MySQL?
To compare DateTime column with only Date, you need to use the Date() method. Following is the syntax. Below, you need to date in the 'yourDateValue':select *from yourTableName where Date(yourColumnName)='yourDateValue';Let us first create a table:mysql> create table DemoTable ( ArrivalTime datetime ); Query OK, 0 rows affected (0.74 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable values('2019-01-31 02:34:56'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('2019-04-09 18:20:58'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('2019-05-11 19:45:23'); Query OK, 1 row affected (0.13 ...
Read MoreHow can I select only those rows where first digit is a number from 0 to 9 in MySQL?
To select only those rows where first digit is a number from 0 to 9, use RLIKE. Following is the syntax −select *from yourTableName where yourColumnName RLIKE '^[0-9]+'Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, QuestionNumber varchar(200) ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(QuestionNumber) values('1Question'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(QuestionNumber) values('Question2'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(QuestionNumber) values('311Question'); Query OK, 1 row affected (0.13 sec) ...
Read MoreMySQL query to delete a record with the lowest ID?
To delete record with the lowest id, you can use the following syntax:delete from yourTableName order by yourColumnName limit 1;Let us first create a table:mysql> create table DemoTable ( Id int, Name varchar(20) ); Query OK, 0 rows affected (0.75 sec)Following is the query to insert records in the table using insert command:mysql> insert into DemoTable values(10, 'Larry'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(100, 'Mike'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(30, 'Sam'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(90, 'Chris'); Query ...
Read MoreWrite a MySQL query where length of the records is longer than 1?
Here, we will use OCTET_LENGTH to check the length of a record since we want the records with length more than 1. Let us first create a table −mysql> create table DemoTable ( UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserName varchar(20), UserGender varchar(20) ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(UserName, UserGender) values('John', 'M'); Query OK, 1 row affected (0.82 sec) mysql> insert into DemoTable(UserName, UserGender) values('Carol', 'Male'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable(UserName, UserGender) values('Mia', 'Female'); Query OK, ...
Read MoreAlter row_format to dynamic in MySQL?
To alter row_format to dynamic in MySQL, following is the syntax:ALTER TABLE yourTableName ROW_FORMAT=DYNAMIC;Let us first create a table:mysql> create table DemoTable ( CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, CustomerName varchar(200), CustomerAge int, CustomerAddress varchar(200) ); Query OK, 0 rows affected (0.73 sec)Let us check the description of table using DESC command:mysql> desc DemoTable;This will produce the following output:+-----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra ...
Read MoreMySQL query to add 0's to numbers with less than 9 digits?
Use LPAD() to add 0's to numbers with less than 9 digits. Let us first create a table −mysql> create table DemoTable ( Value varchar(20) ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('3646465'); Query OK, 1 row affected (0.29 sec) mysql> insert into DemoTable values('9485757591'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('485756'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('959585'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('124'); Query OK, 1 row affected ...
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