Glossary of Common SQL Statements
ALTER DATABASE
ALTER DATABASE database_name;
ALTER DATABASE command changes the size or settings of a database. Its syntax
varies widely among different database systems.
ALTER USER
ALTER USER user
代写留学生论文ALTER USER statement changes a user's system settings such as password.
BEGIN TRANSACTION
1> BEGIN TRANSACTION transaction_name
2> transaction type
3> if exists
4> begin
BEGIN TRANSACTION statement signifies the beginning of a user transaction. A
transaction ends when it is either committed (see COMMIT TRANSACTION) or canceled
(see ROLLBACK TRANSACTION). A transaction is a logical unit of work.
CLOSE CURSOR
close cursor_name
CLOSE cursor_name statement closes the cursor and clears it of data. To completely
remove the cursor, use the DEALLOCATE CURSOR statement.
COMMIT TRANSACTION
SQL> COMMIT;
COMMIT TRANSACTION statement saves all work begun since the beginning of the
transaction (since the BEGIN TRANSACTION statement was executed).
CREATE DATABASE
SQL> CREATE DATABASE database_name;
database_name creates a new database. Many different options can be supplied, such
as the device on which to create the database and the size of the initial database.
CREATE INDEX
CREATE INDEX index_name
ON table_name(column_name1, [column_name2], ...);
the contents of the indexed field(s).
CREATE PROCEDURE
create procedure procedure_name
[[(]@parameter_name
datatype [(length) | (precision [, scale])
[= default][output]
[, @parameter_name
datatype [(length) | (precision [, scale])
[= default][output]]...[)]]
[with recompile]
as SQL_statements
CREATE PROCEDURE statement creates a new stored procedure in the database. This
stored procedure can consist of SQL statements and can then be executed using the
EXECUTE command. Stored procedures support input and output parameters passing
and can return an integer value for status checking.
CREATE TABLE
CREATE TABLE table_name
( field1 datatype [ NOT NULL ],
field2 datatype [ NOT NULL ],
field3 datatype [ NOT NULL ]...)
CREATE TABLE statement creates a new table within a database. Each optional field is
provided with a name and data type for creation within that table.
CREATE TRIGGER
create trigger trigger_name
on table_name
for {insert, update, delete}
as SQL_Statements
CREATE TRIGGER statement creates a trigger object in the database that will execute
its SQL statements when its corresponding table is modified through an INSERT,
UPDATE, or DELETE. Triggers can also call stored procedures to execute complex tasks.
CREATE USER
CREATE USER user
CREATE USER statement creates a new user account complete with user ID and
password.
CREATE VIEW
CREATE VIEW <view_name> [(column1, column2...)] AS
SELECT <table_name column_names>
FROM <table_name>
using the CREATE VIEW statement. After a view is created, it can be queried and data
within the view can be modified.
DEALLOCATE CURSOR
deallocate cursor cursor_name
DEALLOCATE CURSOR statement completely removes the cursor from memory and
frees the name for use by another cursor. You should always close the cursor with the
CLOSE CURSOR statement before deallocating it.
DECLARE CURSOR
declare cursor_name cursor
for select_statement
DECLARE CURSOR statement creates a new cursor from
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