Category Archives: MySQL Tutorial
MySQL is an open source relational database management system (RDBMS) which is widely used worldwide, specially as online database for managing website data. Currently MySQL is the second mostly used RDBMS worldwide. MySQL can be deployed at all major operating systems like Linux, Windows, Solaris, OS X etc.
The Join clause is used to combine data of two or more tables into one temporary table. Joins combine data of two or more tables by common keys.
In order to use joins we normally use at least two tables to fetch data from. One table name is given after select statement while other table name is given after using type of join. The table with select statement is left while the one comes after join clause is considered as right table.
The Group by clause of MySQL, as the name suggests, groups the similar column values, performs some aggregated function (like sum) and returns consolidated result in groups.
The MySQL Order by clause is used with MySQL Select statement to sort results by ascending or descending order. You have to specify one or more columns for what you want to sort mysql table result set.
The Like operator in MySQL is used to search columns data by specified criteria. The like operator uses wildcard character(s) to search in column.
The alter table statement of MySQL is used to Alter existing table structure of MySQL database. You can use MySQL alter table statement to add new columns with column specifications like data-type, size etc.
To retrieve existing data from tables of MySQL database we use Select from statement. A simple select statement without where clause may retrieve whole table data e.g. select * from table_name.
The delete statement of MySQL is used to remove data from tables of MySQL database. The delete statement removes existing data from MySQL tables.
The Update statement is used to update records in MySQL database tables. The update statement updates existing data in table. With a single update command you can update single column of one row, multiple columns data of same row or multiple columns data in multiple rows, as per requirement of your project or scenario.