MySQL中,代表空间索引的关键字是()
A. PRIMARY KEY
B. UNIQUE
C. INDEX
D. SPATIAL
用来限定返回行的查询条件的子句是()
A. WHERE子句
B. ORDER BY 子句
C. LIMIT子句
D. GROUP BY 子句
用来对查询结果进行排序的子句是()
A. WHERE子句
B. ORDER BY 子句
C. LIMIT子句
D. GROUP BY 子句
用来实现对记录分组的子句是()
A. WHERE子句
B. ORDER BY 子句
C. LIMIT子句
D. GROUP BY 子句