tencent cloud

CREATE TABLE user (uid Int16, name String, gender Enum('male'=1, 'female'=2)) ENGINE=Memory;
INSERT INTO user VALUES (1, 'Gary', 'male'), (2, 'Jaco', 'female');
# 查询数据SELECT * FROM user;

┌─uid─┬─name─┬─gender─┐
│   1 │ Gary │ male   │
│   2 │ Jaco │ female │
└─────┴──────┴────────┘
# 使用CAST函数查询枚举整数值SELECT uid, name, CAST(gender, 'Int8') FROM user;

┌─uid─┬─name─┬─CAST(gender, 'Int8')─┐
│   1 │ Gary │                    1 │
│   2 │ Jaco │                    2 │
└─────┴──────┴──────────────────────┘

CREATE TABLE userloginlog (logindate Date, uids Array(String)) ENGINE=TinyLog;
INSERT INTO userloginlog VALUES ('2020-01-02', ['Gary', 'Jaco']), ('2020-02-03', ['Jaco', 'Sammie']);
# 查询结果SELECT * FROM userloginlog;

┌──logindate─┬─uids──────────────┐
│ 2020-01-02 │ ['Gary','Jaco']   │
│ 2020-02-03 │ ['Jaco','Sammie'] │
└────────────┴───────────────────┘

CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster] [ENGINE = engine(...)]
CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
(
    name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1] [compression_codec] [TTL expr1],
    name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2] [compression_codec] [TTL expr2],
    ...
) ENGINE = engine

SELECT [DISTINCT] expr_list
[FROM [db.]table | (subquery) | table_function] [FINAL]
[SAMPLE sample_coeff]
[GLOBAL] [ANY|ALL] [INNER|LEFT|RIGHT|FULL|CROSS] [OUTER] JOIN (subquery)|table USING columns_list
[PREWHERE expr]
[WHERE expr]
[GROUP BY expr_list] [WITH TOTALS]
[HAVING expr]
[ORDER BY expr_list]
[LIMIT [offset_value, ]n BY columns]
[LIMIT [n, ]m]
[UNION ALL ...]
[INTO OUTFILE filename]
[FORMAT format]

INSERT INTO [db.]table [(c1, c2, c3)] VALUES (v11, v12, v13), (v21, v22, v23), ...
INSERT INTO [db.]table [(c1, c2, c3)] SELECT ...

DROP DATABASE [IF EXISTS] db [ON CLUSTER cluster]DROP [TEMPORARY] TABLE [IF EXISTS] [db.]name [ON CLUSTER cluster]
TRUNCATE TABLE [IF EXISTS] [db.]name [ON CLUSTER cluster]

# 对表的列操作
ALTER TABLE [db].name [ON CLUSTER cluster] ADD COLUMN [IF NOT EXISTS] name [type] [default_expr] [codec] [AFTER name_after]ALTER TABLE [db].name [ON CLUSTER cluster] DROP COLUMN [IF EXISTS] nameALTER TABLE [db].name [ON CLUSTER cluster] CLEAR COLUMN [IF EXISTS] name IN PARTITION partition_nameALTER TABLE [db].name [ON CLUSTER cluster] COMMENT COLUMN [IF EXISTS] name 'comment'ALTER TABLE [db].name [ON CLUSTER cluster] MODIFY COLUMN [IF EXISTS] name [type] [default_expr] [TTL]

# 对表的分区操作
ALTER TABLE table_name DETACH PARTITION partition_exprALTER TABLE table_name DROP PARTITION partition_exprALTER TABLE table_name CLEAR INDEX index_name IN PARTITION partition_expr

# 对表的属性操作
ALTER TABLE table-name MODIFY TTL ttl-expression

SHOW DATABASES [INTO OUTFILE filename] [FORMAT format]SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE '<pattern>' | WHERE expr] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]

DESC|DESCRIBE TABLE [db.]table [INTO OUTFILE filename] [FORMAT format]