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Friday, April 16, 2010

Learn Quick SQL syntax

SQL Syntax

Select Statement

SELECT "column_name" FROM "table_name"

Distinct
SELECT DISTINCT "column_name"
FROM "table_name"

Where
SELECT "column_name"
FROM "table_name"
WHERE "condition"

And/Or
SELECT "column_name"
FROM "table_name"
WHERE "simple condition"
{[AND|OR] "simple condition"}+

In
SELECT "column_name"
FROM "table_name"
WHERE "column_name" IN ('value1', 'value2', ...)

Between
SELECT "column_name"
FROM "table_name"
WHERE "column_name" BETWEEN 'value1' AND 'value2'

Like
SELECT "column_name"
FROM "table_name"
WHERE "column_name" LIKE {PATTERN}

Order By
SELECT "column_name"
FROM "table_name"
[WHERE "condition"]
ORDER BY "column_name" [ASC, DESC]

Count
SELECT COUNT("column_name")
FROM "table_name"

Group By
SELECT "column_name1", SUM("column_name2")
FROM "table_name"
GROUP BY "column_name1"

Having
SELECT "column_name1", SUM("column_name2")
FROM "table_name"
GROUP BY "column_name1"
HAVING (arithematic function condition)

Create Table Statement
CREATE TABLE "table_name"
("column 1" "data_type_for_column_1",
"column 2" "data_type_for_column_2",
... )

Drop Table Statement
DROP TABLE "table_name"

Truncate Table Statement
TRUNCATE TABLE "table_name"

Insert Into Statement
INSERT INTO "table_name" ("column1", "column2", ...)
VALUES ("value1", "value2", ...)

Update Statement
UPDATE "table_name"
SET "column_1" = [new value]
WHERE {condition}

Delete From Statement
DELETE FROM "table_name"
WHERE {condition}


Cross Join

A Cross Join is another way to combine two tables.A Cross Join should only be used with small tables.A Cross Join matches every row of the first table with every row of the second table WITHOUT ANY CONDITION., which results in all possible combination's. Cross Joins often generates a lot of data. Cross joins are also called Cartesian products.

Syntax :
----------
SELECT COLUMN_LIST FROM 1ST_TABLE_NAME CROSS JOIN
2ND_TABLE_NAME
Example:
-------------
SELECT L.Name,S.StateId from location L CROSS JOIN state S

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