SQL Function: COUNT()

Definition:

Return the number of records.

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Command Syntax:

COUNT(field_name)

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Command Example:

Table STUDENT

SID	SNAME	CLASS	CNO	MARK
010122	Chris Wong	1A	5	19.4
010141	Gabe Lin	1C	6	35.6
010142	Nico Lin	1C	7	34.8
010133	Amy Chan	2D	12	-97.5
010156	Betty Chan	2E	9	NULL

Input:

SELECT CLASS,COUNT(MARK) AS Result FROM STUDENT GROUP BY CLASS;

Output:

CLASS	Result
1A	1
1C	2
2D	1

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‘COUNT!=SUM’By secondary 6 student