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Whendy

Whendy Blog mengumpulkan beberapa Tutorial Website, PHP, AngularJS, JQuery, Laravel, Codeigniter dan lain-lain. ( jika sempat ) :)

Wildcard Operators – SQL

Wildcard Operators – SQL We already have discussed SQL LIKE operator, which is used to compare a value to similar values using wildcard operators. SQL supports following two wildcard operators in conjunction with the LIKE operator: Wildcards Description The percent sign (%) Matches one or more characters. Note that MS Access uses the asterisk (*) wildcard character instead of the ...

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Transactions – SQL

Transactions – SQL is a unit of work that is performed against a database. Transactions are units or sequences of work accomplished in a logical order, whether in a manual fashion by a user or automatically by some sort of a database program. A transaction is the propagation of one or more changes to the database. For example, if you ...

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Having Clause – SQL

Having Clause – SQL enables you to specify conditions that filter which group results appear in the final results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause. Syntax: The following is the position of the HAVING clause in a query: SELECT FROM WHERE GROUP BY ...

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Using Views – SQL

Using Views – SQL –  is nothing more than a SQL statement that is stored in the database with an associated name. A view is actually a composition of a table in the form of a predefined SQL query. A view can contain all rows of a table or select rows from a table. A view can be created from ...

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TRUNCATE TABLE Command – SQL

TRUNCATE TABLE Command – SQL – is used to delete complete data from an existing table. You can also use DROP TABLE command to delete complete table but it would remove complete table structure form the database and you would need to re-create this table once again if you wish you store some data. Syntax: The basic syntax of TRUNCATE ...

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ALTER TABLE Command – SQL

ALTER TABLE Command – SQL is used to add, delete or modify columns in an existing table. You would also use ALTER TABLE command to add and drop various constraints on a an existing table. Syntax: The basic syntax of ALTER TABLE to add a new column in an existing table is as follows: ALTER TABLE table_name ADD column_name datatype; ...

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Indexes – SQL

Indexes are special lookup tables that the database search engine can use to speed up data retrieval. Simply put, an index is a pointer to data in a table. An index in a database is very similar to an index in the back of a book. For example, if you want to reference all pages in a book that discuss ...

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Alias Syntax – SQL

Alias Syntax – SQL — You can rename a table or a column temporarily by giving another name known as alias. The use of table aliases means to rename a table in a particular SQL statement. The renaming is a temporary change and the actual table name does not change in the database. The column aliases are used to rename ...

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NULL Values – SQL

NULL Values – SQL is the term used to represent a missing value. A NULL value in a table is a value in a field that appears to be blank. A field with a NULL value is a field with no value. It is very important to understand that a NULL value is different than a zero value or a field ...

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UNIONS CLAUSE – SQL

UNIONS CLAUSE – SQL is used to combine the results of two or more SELECT statements without returning any duplicate rows. To use UNION, each SELECT must have the same number of columns selected, the same number of column expressions, the same data type, and have them in the same order, but they do not have to be the same ...

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