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Search Database #1 (SQL Where
clauses)
There are several ways to search the data using pure SQL once
we review the simple rules of how a WHERE clause works.
- Text fields must be enclosed in single quotes, i.e.
"select * from publishers where state='MD'
- Numeric fields need no special characters before and after
"select * from publishers where PubID=10"
- If you aren't sure how to spell the text field or are looking
for sound alikes, LIKE supports %% wildcards
"select * from publishers where Name like 'A%%'"
These basic WHERE clause guidelines
above are the fundamental building block of searches.
It is also helpful to utilize the equality operators, i.e.
| <> |
not equal |
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| > |
greater than |
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| < |
less than |
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| >= |
greater than OR equal |
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| <= |
less than or equal |
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- Numeric fields benefit most from the equality operators:
"select * from publishers where PubID>10"
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