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Thursday, 4 July 2013

CREATE a table from another table

You can also create a table from an existing table by copying the existing table's
columns.

It is important to note that when creating a table in this way, the new table will be
populated with the records from the existing table (based on the SELECT Statement).

Syntax #1 - Copying all columns from another table

The basic syntax is:

CREATE TABLE new_table
AS (SELECT * FROM old_table);

For example:

CREATE TABLE suppliers
AS (SELECT *
FROM companies
WHERE id > 1000);

This would create a new table called suppliers that included all columns from the
companies table.

If there were records in the companies table, then the new suppliers table would also
contain the records selected by the SELECT statement.

Syntax #2 - Copying selected columns from another table

The basic syntax is:

CREATE TABLE new_table
AS (SELECT column_1, column2, ... column_n FROM old_table);

For example:

CREATE TABLE suppliers
AS (SELECT id, address, city, state, zip
FROM companies
WHERE id > 1000);

This would create a new table called suppliers, but the new table would only include the
specified columns from the companies table.

Again, if there were records in the companies table, then the new suppliers table would
also contain the records selected by the SELECT statement.

Syntax #3 - Copying selected columns from multiple tables

The basic syntax is:

CREATE TABLE new_table
AS (SELECT column_1, column2, ... column_n
FROM old_table_1, old_table_2, ... old_table_n);

For example:

CREATE TABLE suppliers
AS (SELECT companies.id, companies.address, categories.cat_type
FROM companies, categories
WHERE companies.id = categories.id
AND companies.id > 1000);

This would create a new table called suppliers based on columns from both the
companies and categories tables.

Frequently Asked Questions

Question: How can I create a table from another table without copying any values from
the old table?

Answer: To do this, the basic syntax is:

CREATE TABLE new_table
AS (SELECT * FROM old_table WHERE 1=2);

For example:

CREATE TABLE suppliers
AS (SELECT * FROM companies WHERE 1=2);

This would create a new table called suppliers that included all columns from the
companies table, but no data from the companies table.

Download CREATEatablefromanothertable.pdf.html

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