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MySQLi Articles
Page 128 of 341
Create table query with manual AUTO_INCREMENT start value in MySQL?
Let us first create a table −mysql> create table DemoTable1907 ( UserId int NOT NULL AUTO_INCREMENT, UserName varchar(20), UserAge int, UserCountryName varchar(20), PRIMARY KEY(UserId) )ENGINE=MyISAM, AUTO_INCREMENT=100; Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('Chris', 26, 'US'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('David', 38, 'UK'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1907(UserName, UserAge, UserCountryName) values('John', 28, 'AUS'); Query OK, 1 row affected (0.00 sec)Display all records from the ...
Read MoreMySQL Count Distinct values process is very slow. How to fasten it?
To fasten the process, you can use INDEX. Let us first create a table −mysql> create table DemoTable1905 ( FirstName varchar(20), LastName varchar(20) , INDEX F_L_Name(FirstName, LastName) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1905 values('John', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('John', 'Doe'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('Adam', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1905 values('John', 'Doe'); Query OK, 1 row affected (0.00 sec) ...
Read MoreHow to escape backslashes in MySQL with JDBC?
To escape backslashes, use PreparedStatement while inserting records. Let us first create a table −mysql> create table DemoTable1904 ( ClientId int, ClientName varchar(20), ClientAge int ); Query OK, 0 rows affected (0.00 sec)The Java code is as follows −import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; public class EscapeBackslashesDemo { public static void main(String[] args) { Connection con = null; PreparedStatement ps = null; try { con = DriverManager.getConnection("jdbc:mysql://localhost:3306/web?" + "useSSL=false", "root", "123456"); String query = "insert into DemoTable1904(ClientId, ...
Read MoreMySQL UPDATE column names and set None values with N/A?
Let us first create a table −mysql> create table DemoTable1903 ( FirstName varchar(20), LastName varchar(20) , Age int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1903 values('John', 'Smith', 23); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None', 'Miller', 28); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('None', 'Taylor', 26); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1903 values('Chris', 'Brown', 26); Query OK, 1 row affected (0.00 sec)Display all records from the table ...
Read MoreMySQL ORDER BY with numeric user-defined variable?
Let us first create a table −mysql> create table DemoTable1898 ( Number int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1898 values(10); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(70); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(30); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(50); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1898 values(40); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement ...
Read MoreGet field value and convert a particular character from it to uppercase with MySQL
Let us first create a table −mysql> create table DemoTable1897 ( Name varchar(20) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1897 values('john'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('jace'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('David'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('Chris'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement ...
Read MoreGet only a single value from a specific MySQL row?
For this, use SELECT INTO variable with where clause. Let us first create a table −mysql> create table DemoTable1896 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(20), StudentMarks int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Chris', 56); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('David', 98); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Mike', 89); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Sam', ...
Read MoreWhat to assign to a MySQL column that must not be empty?
Define with NOT NULL, if a column must not be empty. Let us first create a table with one of the columns as NOT NULL −mysql> create table DemoTable1895 ( Id int NOT NULL, FirstName varchar(20), LastName varchar(20) NOT NULL ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1895 values(100, 'John', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1895 values(NULL, 'Chris', 'Brown'); ERROR 1048 (23000): Column 'Id' cannot be null mysql> insert into DemoTable1895 values(102, 'Carol', NULL); ERROR 1048 (23000): ...
Read MoreSet a MySQL field with the current date (UNIX_TIMESTAMP(now))
For this, use unix_timestamp(). Let us first create a table −mysql> create table DemoTable1894 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, DueTime int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1894;This will produce the following output −+----+---------+ | ...
Read MoreCan you allow a regex match in a MySQL Select statement?
Yes, we can do regex match in a select statement −select yourColumnName from yourTableName where yourColumnName regexp '^yourValue';Let us first create a table −mysql> create table DemoTable1892 ( FirstName varchar(20) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1892 values('John'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Adam'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Jace'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Johny'); Query OK, 1 row affected (0.00 sec) mysql> insert into ...
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