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create table t(a int, b char, key (a,b));
describe t;
| Field | Type | Null | Key | Default | Extra |
|---|---|---|---|---|---|
| a | 696e74 | YES | MUL | null | |
| b | 63686172283129 | YES | null |
SHOW INDEXES FROM t
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| t | 1 | a | 1 | a | A | 0 | null | null | YES | BTREE | YES | null | ||
| t | 1 | a | 2 | b | A | 0 | null | null | YES | BTREE | YES | null |