MySQL SQLLesson 7Free preview

MySQL WHERE

This lesson is part of MySQL · All levels

Summary

The WHERE clause is used to filter the row to only meet certain conditions that are involved in the processing. The condition can compare the column with a fixed value or the result of a function, e.g. price > 10000 or date_list >= '2024-01-01'. In MySQL, a string is enclosed with a single quotation mark, whereas a double quotation mark is only used for identifiers such as a special table or column name.

Key points

WHERE is placed after FROM and before ORDER BY or LIMIT
Common comparison operators: =, <>, >, <, >=, <=
The value text and date must be enclosed with a single quotation mark
Row with value NULL cannot be compared using = and should be checked with IS NULL

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