SQL function
SQL has many built-in functions that can be used for counting and calculating.
SQL Aggregate function
The SQL Aggregate function calculates the value obtained from the column and returns a single value.
Useful Aggregate function:
- AVG() - Returns an average
- COUNT() - Returns the number of rows
- FIRST() - Returns the value of the first record
- LAST() - Returns the value of the last record
- MAX() - Returns the maximum value
- MIN() - Returns the minimum value
- SUM() - Returns the sum
SQL Scalar function
The SQL Scalar function returns a single value based on the input value.
Useful Scalar function:
- UCASE() - Converts a field to capital
- LCASE() - Converts a field to lesscase
- MID() - Extract characters from a text field
- LEN() - Returns the length of a text field
- ROUND() - Rounds a numeric field by specifying the scale
- NOW() - Returns the current system date and time
- FORMAT() - Format how a field is displayed
Tip: In the following sections, we'll cover the Aggregate and Scalar functions in more detail.
Chapter test
Now, take a look at how well you know sql functions with the following topics!
SQL Functions: In this section of the quiz, you'll practice using SQL functions.
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