Wildcards
September 13, 1998
As in most languages, SQL provides a set of
wildcards that are used as shortcuts to represent whole
categories of values. For example,
oftentimes, you may want all the data for the columns
in your table but you don't want to write all the column names
in a comma-delimited list.
To make such queries more efficient,
SQL provides the "*" wildcard that specifies "ALL" of something.
For example, to select all the columns in the
PRODUCTS table, we
would use:
SELECT *
FROM PRODUCTS;
The database would then respond with:
P_NUM P_QUANTITY P_PRICE
-------------------------------
001 104 99.99
002 12 865.99
003 2000 50.00
-------------------------------
Of course you could achieve the same
results (with more work) using:
SELECT P_NUM, P_QUANTITY, P_PRICE
FROM PRODUCTS;
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