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MySQLi Articles
Page 34 of 341
Copy a few columns from a table to another in MySQL
Let us first create a table −mysql> create table DemoTable1 -> ( -> Id int, -> Name varchar(100) -> ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(10, 'John'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable1 values(11, 'Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1 values(12, 'Robert'); Query OK, 1 row affected (0.32 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+------+--------+ | Id ...
Read MoreHow to select the sum of the column values with higher value in reach row with MySQL?
Use the CASE statements and set conditions for the same. Let us first create a table −mysql> create table DemoTable -> ( -> X int, -> Y int -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(20, 30); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(40, 15); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(80, 85); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select ...
Read MoreMySQL query to display structure of a table
To display structure of a table, following is the syntax −show create table yourTableName;Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> EmployeeFirstName varchar(100), -> EmployeeLastName varchar(100), -> EmployeeAge int, -> isMarried tinyint(1), -> EmployeeAddress varchar(100), -> EmployeeCountryName varchar(100) -> ); Query OK, 0 rows affected (0.62 sec)Here is the query to display structure −mysql> show create table DemoTable;OutputThis will produce the following output −+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table ...
Read MoreMultiple column sorting in MySQL?
Let us first create a table −mysql> create table DemoTable -> ( -> Id int, -> Value int -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 85885); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(101, 885995474); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(100, 895943); Query OK, 1 row affected (0.20 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+------+-----------+ | Id ...
Read MoreHow do I multiply an unsigned int by -1 on a MySQL SELECT?
Let us first create a table −mysql> create table DemoTable -> ( -> Value int -> ); Query OK, 0 rows affected (0.80 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+-------+ | Value | +-------+ | 10 | | ...
Read MoreOrder by number of chars in MySQL?
To order by number of chars, use ORDER BY and LENGTH() method. Following is the syntax −select *from yourTableName order by LENGTH(yourColumnName) DESC;Let us first create a table −mysql− create table DemoTable -> ( -> Name varchar(100) -> ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Bob'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable ...
Read MoreHow to concatenate MySQL distinct query results into a string?
Use group_concat() function from MySQL to concatenate. Let us first create a table −mysql> create table DemoTable -> ( -> Subject varchar(10) -> ); Query OK, 0 rows affected (0.43 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('C'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('C++'); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable values('C++'); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable values('MongoDB'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('MySQL'); Query ...
Read MoreGet only digits using regexp in MySQL?
If you want to get only digits using REGEXP, use the following regular expression( ^[0-9]*$) in where clause.Case 1 − If you want only those rows which have exactly 10 digits and all must be only digit, use the below regular expression.SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[0-9]{10}$';Case 2 − If you want only those rows with the digit either 1 or more, the following is the syntax −SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[0-9]*$';The above syntax will give only those rows that do not have any any characters.To understand the above syntax, let us create a table. The query ...
Read MoreFetch rows where first character is not alphanumeric in MySQL?
To fetch rows where first character is not alphanumeric, you can use the following regular expression.Case 1 − If you want those rows that starts from a digit, you can use the following syntax −SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[0-9]';Case 2 − If you want those rows that start from an alphanumeric, use the following syntax −SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[^0-9A-Za-z]' ;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table getRowsFirstNotAlphanumeric -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserPassword varchar(20), -> PRIMARY ...
Read MoreHow to update data in a MySQL database without removing the old data?
For this, you can use UPDATE and concatenate the new data with the old one to save the old data as well −update yourTableName set yourColumnName=concat(yourColumnName, ", yourValue");Let us first create a table −mysql> create table DemoTable -> ( -> CustomerName varchar(100) -> ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('Sam'); Query OK, 1 row affected (0.14 sec)Display all records from ...
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