删除MySQL表是否会自动删除该表的索引？

Question

删除MySQL表是否会自动删除该表的索引？

Answer 1

是.它删除了索引.这可以验证:

CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo);
CREATE INDEX ix_table1_foo ON table1 (foo); -- fails: index already exists.
DROP TABLE table1;
CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo); -- succeeds: index does not exist.

您还可以通过查看信息架构来验证它:

CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo);

SELECT COUNT(*)
FROM information_schema.STATISTICS
WHERE INDEX_NAME = 'ix_table1_foo';  -- returns 1

DROP TABLE table1;

SELECT COUNT(*)
FROM information_schema.STATISTICS
WHERE INDEX_NAME = 'ix_table1_foo';  -- returns 0