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MySQLi Articles
Page 293 of 341
How to auto-increment value of tables to lower value in MySQL?
If you’re using InnoDB engine, then you cannot set auto_increment value of tables to lower value. You need to change your engine from InnoDB to MyISAM.Note: The engine MyISAM allows you to set lower value. Here, we are using the same.According to the official documents:You cannot reset the counter to a value less than or equal to any that have already been used. For MyISAM, if the value is less than or equal to the maximum value currently in the AUTO_INCREMENT column, the value is reset to the current maximum plus one. For InnoDB, if the value is less than ...
Read MoreHow to return today's records using DATE from DATETIME Field?
Let us first create a table in which one of the column is of datetime type;mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, ShippingDate datetime ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command.mysql> insert into DemoTable(ShippingDate) values('2019-03-01 05:45:32'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(ShippingDate) values('2019-04-13 11:34:56'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(ShippingDate) values('2019-03-15 04:45:23'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(ShippingDate) values('2019-04-11 12:10:02'); Query OK, 1 row affected (0.17 sec)Following is the ...
Read MoreHow to use COUNT(*) to return a single row instead of multiple?
You need to use GROUP BY with COUNT(*) for this to group the values and display the count eliminating multiple values. Let us first create a table:mysql> create table DemoTable (Value int); Query OK, 0 rows affected (0.55 sec)Following is the query to insert some records in the table using insert command:mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.14 sec) mysql> ...
Read MoreMySQL query to get max id from varchar type and the values in numeric?
Use CAST() in MAX() to get max id from varchar type and values in numeric. Let us first create a table. Here, we have a column with varchar type −mysql> create table DemoTable ( UserMarks varchar(20) ); Query OK, 0 rows affected (0.77 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('77'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('98'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('45'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('56'); Query OK, 1 row affected (0.18 ...
Read MoreApply 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) ...
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