MySQLi Articles - Page 29 of 341

How to escape backslashes in MySQL with JDBC?

AmitDiwan
Updated on 30-Dec-2019 06:17:55

435 Views

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 More

MySQL UPDATE column names and set None values with N/A?

AmitDiwan
Updated on 30-Dec-2019 06:14:54

321 Views

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 More

MySQL ORDER BY with numeric user-defined variable?

AmitDiwan
Updated on 27-Dec-2019 07:05:19

420 Views

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 More

Get field value and convert a particular character from it to uppercase with MySQL

AmitDiwan
Updated on 27-Dec-2019 07:04:08

152 Views

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 More

Mobile

Get only a single value from a specific MySQL row?

AmitDiwan
Updated on 27-Dec-2019 07:02:32

2K+ Views

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 More

What to assign to a MySQL column that must not be empty?

AmitDiwan
Updated on 27-Dec-2019 06:58:48

441 Views

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 More

Set a MySQL field with the current date (UNIX_TIMESTAMP(now))

AmitDiwan
Updated on 27-Dec-2019 06:57:19

602 Views

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 More

Java application to insert null value into a MySQL database

Alshifa Hasnain
Updated on 10-Oct-2024 11:36:15

1K+ Views

In this program, we will connect to a MySQL database and insert a null value into a table using Java's JDBC API. We will use the PreparedStatement class along with the setNull() method to achieve this. After the value is inserted, you can check the table to see how the null value is reflected. Steps to insert null value into a MySQL database Following are the steps to insert null value into a MySQL database − Establish a connection to the MySQL database using the DriverManager.getConnection() method. Define the SQL query that ... Read More

Can you allow a regex match in a MySQL Select statement?

AmitDiwan
Updated on 27-Dec-2019 06:51:28

198 Views

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 ... Read More

MySQL Stored procedure to declare two values and perform mathematical operation

AmitDiwan
Updated on 27-Dec-2019 06:50:21

958 Views

Let us first create a stored procedure −mysql> delimiter // mysql> create procedure declare_demo_sp()    begin    declare Value1 int;    declare Value2 int;    set Value1=100;    set Value2=2000;    select Value1,Value2,Value1*Value2 as MultiplicationResult;    end    // Query OK, 0 rows affected (0.00 sec) mysql> delimiter ;Call a stored procedure using CALL command −mysql> call declare_demo_sp();This will produce the following output −+--------+--------+----------------------+ | Value1 | Value2 | MultiplicationResult | +--------+--------+----------------------+ |    100 |   2000 |               200000 | +--------+--------+----------------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.00 sec)

Advertisements