Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
MySQL Articles
Page 157 of 355
Easiest way to get number of rows in a MySQL table?
The easiest way to get number of rows, use aggregate function COUNT(*). Let us first create a table −mysql> create table DemoTable1575 -> ( -> FirstName varchar(20) -> ); Query OK, 0 rows affected (1.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1575 values('Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1575 values('Bob'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1575 values('Adam'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1575 values('Robert'); Query OK, 1 row affected (0.15 sec)Display all records from the table ...
Read MoreMySQL query to replace special characters from column value
Let us first create a table −mysql> create table DemoTable1574 -> ( -> StudentCode varchar(20) -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1574 values('111_Carol'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1574 values('______'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable1574 values('David_12345'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1574 values('______'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select * from DemoTable1574;This will produce the following ...
Read MoreHow to order or choose rows in MySQL GROUP BY clause?
Let us first create a table −mysql> create table DemoTable1572 -> ( -> StudentId int, -> StudentMarks int, -> StudentName varchar(20) -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1572 values(1, 79, 'Sam'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1572 values(2, 89, 'Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1572 values(3, 98, 'David'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable1572 values(4, 79, 'Bob'); Query OK, 1 row affected (0.10 sec)Display all ...
Read MoreWhat is the proper way to insert an IF statement into a MySQL query?
To insert an IF statement into a MySQL query, use the below syntax::select yourColumnName ,if(yourCondition, yourStatement1, yourStatement2) from yourTableName;Let us first create a table −mysql> create table DemoTable1571 -> ( -> Id int, -> Value int -> ); Query OK, 0 rows affected (5.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1571 values(101, 500); Query OK, 1 row affected (1.07 sec) mysql> insert into DemoTable1571 values(102, 450); Query OK, 1 row affected (0.47 sec) mysql> insert into DemoTable1571 values(103, 300); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1571 ...
Read MoreHow to make a MySQL Connection in JAVA? What is the port number to set on locahost?
You need to use port number 3306 in the URL. The syntax is as follows −jdbc:mysql://localhost:3306Exampleimport java.sql.Connection; import java.sql.DriverManager; public class MySQLConnectionToJava { public static void main(String[] args) { String JDBCURL="jdbc:mysql://localhost:3306/sample?useSSL=false"; Connection con=null; try { con = DriverManager.getConnection(JDBCURL,"root","123456"); if(con!=null) { System.out.println("MySQL connection is successful with port 3306."); } } catch(Exception e) { e.printStackTrace(); } } }OutputMySQL connection is successful with port 3306.
Read MoreMySQL insert a value to specific row and column
Let us first create a table −mysql> create table DemoTable1569 -> ( -> StudentId varchar(10), -> StudentName varchar(20) -> ); Query OK, 0 rows affected (3.05 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1569 values('John_12', 'John Smith'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable1569 values('David_321', 'Carol Taylor'); Query OK, 1 row affected (0.50 sec) mysql> insert into DemoTable1569 values('David_989', 'David Miller'); Query OK, 1 row affected (0.24 sec)Display all records from the table using select statement −mysql> select * from DemoTable1569;This will produce the following output+-----------+--------------+ | ...
Read MoreFinding total number of rows of tables across multiple databases in MySQL?
To fetch total number of table rows across databases, use aggregate function SUM() along with INFORMATION SCHEMA. Let us first create a table, which is in “web” database −mysql> create table DemoTable1568 -> ( -> Name varchar(20) -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1568 values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1568 values('Bob'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1568 values('David'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select ...
Read MoreGetting the last 30 rows in MySQL
To get the last 30 rows in MySQL, you need to use ORDER BY DESC and then LIMIT 30. The syntax is as follows −select * from yourTableName order by yourColumnName DESC LIMIT 30;Let us first create a table −mysql> create table DemoTable1567 -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY -> ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1567 values(), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), ...
Read MoreUsing CASE statement in MySQL to display custom name for empty value
For this, you can use CASE WHEN statement. Let us first create a table −mysql> create table DemoTable -> ( -> Name varchar(20) -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.11 sec)Display all records from the table using select statement −mysql> ...
Read MoreMySQL query to display custom text for empty columns
Let us first create a table −mysql> create table DemoTable -> ( -> FirstName varchar(20) -> ); Query OK, 0 rows affected (0.77 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Bob'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.13 sec)Display all records from the table ...
Read More