Creada el: 28/09/98 - Actualizada el: 28/09/98
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ALTER DATABASE Statement
Increases the amount of disk space allocated to a database.
ALTER DATABASE <database_name>
[ON {DEFAULT | <database_device>} [= <size>]
[, <database_device> [= <size>]]...]
[FOR LOAD]
test
ALTER TABLE Statement
Adds new columns or constraints to an existing table.
ALTER TABLE <database>.[<owner>.]<table_name>
[WITH {CHECK | NOCHECK}]
{{CHECK | NOCHECK} CONSTRAINT
{<constraint_name> | ALL} |
[ADD
{<col_name> <column_properties> [<column_constraints>]
| [[,] <table_constraint>]}
[, {<next_col_name> | <next_table_constraint>}]...]
|
[DROP CONSTRAINT]
<constraint_name> [, <constraint_name2>]...]}
<column_properties> =
<datatype> [NULL | IDENTITY[(<seed>, <increment>)]]
<column_constraints> =
For a column-level constraint:
[CONSTRAINT <constraint_name> ]
{PRIMARY KEY [CLUSTERED | NONCLUSTERED][ (<col_name>)]
| UNIQUE [CLUSTERED | NONCLUSTERED] [(<col_name>)]
[WITH FILLFACTOR = <fillfactor> ]
| FOREIGN KEY [(<col_name>)]
REFERENCES [(<ref_col>)][NOT FOR REPLICATION]
| CHECK [NOT FOR REPLICATION] (<expression>)}
<table_constraints> =
For a table-level constraint:
[CONSTRAINT <constraint_name> ]
{PRIMARY KEY [CLUSTERED | NONCLUSTERED]
(<col_name> [, <col_name2> [..., <col_name16>]])
| UNIQUE [CLUSTERED | NONCLUSTERED]
(<col_name> [, <col_name2> [..., <col_name16>]])
[WITH FILLFACTOR = <fillfactor>]
| FOREIGN KEY (<col_name> [, <col_name2> [..., <col_name16>]])
REFERENCES [<owner>.]<ref_table> (<ref_col>
[, <ref_col2> [..., <ref_col16>]])
[NOT FOR REPLICATION]
| CHECK [NOT FOR REPLICATION] (<expression>)}
BEGIN DISTRIBUTED TRANSACTION Statement
Used to start a transaction that is processed on one or
more remote servers. MS DTC manages the distributed transaction.
BEGIN DISTRIBUTED TRANSACTION [<transaction_name>]
BEGIN TRANSACTION Statement
Marks the starting point of a user-specified transaction.
BEGIN TRANsaction [<transaction_name>]
BEGIN...END Block
Encloses a series of SQL statements so that control-of-flow language,
such as IF...ELSE, affects the performance of a group of statements
instead of only the statement that immediately follows.
BEGIN...END blocks can be nested.
BEGIN
{sql_statement | <statement_block>}
END
CASE Expression
The CASE expression allows SQL expressions to be simplified for
conditional values. The CASE expression in SQL Server 6.0 is ANSI
SQL-92-compliant and allowed anywhere an expression is used.
Simple CASE expression:
CASE <expression>
WHEN <expression1> THEN <expression1>
[[WHEN <expression2> THEN <expression2>] [...]]
[ELSE <expressionN>]
END
Searched CASE expression:
CASE
WHEN <Boolean_expression1> THEN <expression1>
[[WHEN <Boolean_expression2> THEN <expression2> ] [...]]
[ELSE <expressionN>]
END
CASE-related functions:
COALESCE (<expression1>, <expression2>)
COALESCE (<expression1>, <expression2>, ... <expressionN>)
NULLIF (<expression1>, <expression2>)
CHECKPOINT Statement
Forces all dirty pages (those that have been updated since the
last checkpoint) in the current database to be written to disk.
CHECKPOINT
CLOSE Statement
Closes an open cursor. CLOSE leaves the data structures accessible for
reopening; however, modifications or fetches are not allowed until the
cursor is reopened.
CLOSE <cursor_name>
Comments Provide user-documented information about SQL statements, statement blocks, and stored procedures. /* <text of comment> */ Or -- <text of comment>
COMMIT TRANSACTION Statement
Marks the end of a user-defined transaction.
COMMIT TRANsaction [<transaction_name>]
Control-of-Flow Language
Controls the flow of execution of SQL statements, statement blocks, and
stored procedures. These keywords can be used in ad hoc SQL
statements, in batches, and in stored procedures.
These are the control-of-flow keywords:
BEGIN...END Defines a statement block.
GOTO <label> Continues processing at the statement following the
label as defined by <label>.
IF...ELSE Defines conditional and, optionally, alternate
execution when a condition is false.
RETURN Exits unconditionally.
WAITFOR Sets a delay for statement execution.
WHILE Repeats statements while a specific condition is true.
...BREAK Exits the innermost WHILE loop.
...CONTINUE Restarts a WHILE loop.
CREATE DATABASE Statement
Creates a new database. You must be in the master database to create a
new database.
CREATE DATABASE <database_name>
[ON {DEFAULT | <database_device>} [= <size>]
[, <database_device> [= <size>]]...]
[LOG ON <database_device> [= <size>]
[, <database_device> [= <size>]]...]
[FOR LOAD]
CREATE DEFAULT Statement
Creates an object that, when bound to a column or a user-defined
datatype, specifies a value to be inserted into the column to which it's
bound (or into all columns in the case of a user-defined datatype) when
no value is explicitly supplied during an insert.
CREATE DEFAULT [<owner>.]<<default_name>>
AS <constant_expression>
CREATE INDEX Statement
Creates an index on a given table that either changes the physical
ordering of the table or provides the optimizer with a logical ordering
of the table to increase efficiency for queries.
CREATE [UNIQUE] [CLUSTERED | NONCLUSTERED] INDEX <index_name>
ON [[<database>.]<owner>.]<table_name> (<column_name>
[, <column_name>]...)
[WITH
[PAD_INDEX,]
[[,]FILLFACTOR = <fillfactor>]
[[,] IGNORE_DUP_KEY]
[[,] SORTED_DATA | SORTED_DATA_REORG]
[[,] IGNORE_DUP_ROW | ALLOW_DUP_ROW]]
[ON <segment_name>]
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Por Luis Walter Reynoso para Ethek & Friends