Appendix D. Â
Symbols
= >< > < >= <=
Youâve got a whole bunch of equality and inequality operators at your disposal.
A
ALTER with CHANGE
Lets you change both the name and data type of an existing column.
ALTER with MODIFY
Lets you change just the data type of an existing column.
ALTER with ADD
Lets you add a column to your table in the order you choose.
ALTER with DROP
Lets you drop a column from your table.
ALTER TABLE
Lets you change the name of your table and its entire structure while retaining the data inside of it.
AND and OR
With AND and OR, you can combine your conditional statements in your WHERE clauses for more precision.
ATOMIC DATA
Data in your columns is atomic if itâs been broken down into the smallest pieces that you need.
ATOMIC DATA RULE 1
Atomic data canât have several bits of the same type of data in the same column.
ATOMIC DATA RULE 2
Atomic data canât have multiple columns with the same type of data.
AUTO_INCREMENT
When used in your column declaration, that column will automatically be given a unique integer value each time an INSERT command is performed.
AVG
Returns the average value in a numeric column.
C
CHECK CONSTRAINTS
Use these to only allow specific values to be inserted or updated in a table.
CHECK OPTION
Use this when creating an updatable view to force all inserts and updates to satisfy ...
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