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 MySQL, Oracle, MS SQL Server, Microsoft Access, MSDE, DB2, Sybase, 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.
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.
| Introduction to SQL | |
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SQL is a
standard computer language for accessing and manipulating databases.
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| SQL SELECT Statement | |
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The SELECT
statement is used to select data from a table. The tabular result is
stored in a result table (called the result-set).
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| SQL WHERE Clause | |
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The WHERE
clause is used to specify a selection criterion.
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| SQL INSERT INTO Statement | |
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The INSERT
INTO statement is used to insert new rows into a table.
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| SQL UPDATE Statement | |
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The UPDATE
statement is used to modify the data in a table.
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| SQL DELETE Statement | |
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The DELETE
statement is used to delete rows in a table.
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| SQL ORDER BY | |
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The ORDER BY
keyword is used to sort the result.
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| SQL AND & OR | |
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AND and OR
join two or more conditions in a WHERE clause.
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| SQL IN | |
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The IN
operator may be used if you know the exact value you want to return for at
least one of the columns.
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| SQL BETWEEN | |
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The BETWEEN
... AND operator selects a range of data between two values. These values
can be numbers, text, or dates.
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| SQL Alias | |
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With SQL,
aliases can be used for column names and table names.
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| SQL JOIN | |
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Sometimes we
have to select data from two or more tables to make our result complete.
We have to perform a join.
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| SQL UNION and UNION ALL | |
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The UNION
command is used to select related information from two tables, much like
the JOIN command. However, when using the UNION command all selected
columns need to be of the same data type.
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| SQL Create Database, Table, and Index | |
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Learn how to
create Databases, Tables, and Indexes.
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| SQL Drop Index, Table and Database | |
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Learn how to
delete
Indexes, Tables, and Databases.
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| SQL ALTER TABLE | |
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The ALTER
TABLE statement is used to add or drop columns in an existing table.
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| SQL Functions | |
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SQL has a lot
of built-in functions for counting and calculations.
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| SQL GROUP BY and HAVING | |
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Aggregate
functions (like SUM) often need an added GROUP BY functionality.
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| SQL SELECT INTO Statement | |
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The SELECT
INTO statement is most often used to create backup copies of tables or for
archiving records.
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| SQL CREATE VIEW Statement | |
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A view is a
virtual table based on the result-set of a SELECT statement.
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| SQL Servers - RDBMS | |
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Modern SQL
Servers are built on RDBMS.
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| SQL Quick Reference | |
| SQL Quick Reference. Print it, and fold it in your pocket. | |