SQL Tutorial
SQL is short for Structured Query Language and is a widely
used database language, providing means of data manipulation (store, retrieve,
update, delete) and database creation.
Almost all modern Relational Database Management Systems like MS SQL Server,
Microsoft Access, MSDE, Oracle, DB2, Sybase, MySQL, Postgres and Informix use
SQL as standard database language. Now a word of warning here, although all
those RDBMS use SQL, they use different SQL dialects. For example MS SQL Server
specific version of the SQL is called T-SQL, Oracle version of SQL is called
PL/SQL, MS Access version of SQL is called JET SQL, etc.
Our SQL tutorial will teach you how to use commonly used SQL commands and you
will be able to apply most of the knowledge gathered from this SQL tutorial to
any of the databases above.
SQL Tutorial Table of Contents
SQL Tutorial
Learn what SQL (Structured Query Language) is, and where and how it is used.
SQL
Table
SQL Database Tables are the foundation of every RDBMS (Relational Database
Management System). Learn more about SQL tables here.
SQL SELECT
Learn how to use the SELECT SQL statement to retrieve data from a SQL database
table.
SQL SELECT
INTO
Learn how to use the SQL SELECT INTO statement to copy data between database tables.
SQL DISTINCT
Learn how to use the SQL DISTINCT clause together with the SQL SELECT keyword, to return
a dataset with unique entries for certain database table column.
SQL WHERE
The SQL WHERE command is used to specify selection criteria, thus restricting
the result of a SQL query.
SQL LIKE
The SQL LIKE clause is used along with the SQL WHERE clause and specifies
criteria based on a string pattern.
SQL INSERT
INTO
Learn how to use the SQL INSERT INTO clause to insert data into a SQL database
table.
SQL UPDATE
Learn how to use the SQL UPDATE statement to update data in a SQL database table.
SQL DELETE
Learn how to use the SQL DELETE statement to delete data from a SQL database table.
SQL ORDER BY
Learn how to use the SQL ORDER BY statement to sort the data retrieved in your SQL
query.
SQL OR & AND
Learn how to use the SQL OR & AND keywords together with the SQL WHERE clause to
add several conditions to your SQL statement.
SQL IN
The SQL IN clause allows you to specify discrete values in your SQL WHERE
search criteria.
SQL BETWEEN
The SQL BETWEEN & AND keywords define a range of data between 2 values.
SQL Aliases
SQL aliases can be used with database tables and/or with database table
columns, depending on task you are performing.
SQL COUNT
The SQL COUNT aggregate function is used to count the number of rows in a database table.
SQL MAX
The SQL MAX aggregate function allows us to select the highest (maximum) value for a certain column.
SQL MIN
The SQL MIN aggregate function allows us to select the lowest (minimum) value for a certain column.
SQL AVG
The SQL AVG aggregate function selects the average value for a certain table column.
SQL SUM
The SQL SUM aggregate function allows selecting the total for a numeric column.
SQL GROUP BY
The SQL GROUP BY statement is used along with the SQL aggregate functions like
SUM to provide means of grouping the result dataset by certain database table
column(s).
SQL HAVING
The SQL HAVING clause is used to restrict conditionally the output of a SQL
statement, by a SQL aggregate function used in your SELECT list of columns.
SQL JOIN
The SQL JOIN clause is used whenever we have to select data from 2 or more tables.
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