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Beispielanalyse für einen einspaltigen MySQL-Speicher mit mehreren Werten

WBOY
WBOYnach vorne
2023-05-29 17:46:291454Durchsuche

    Beispiel

    Bittyp

    • zum Erstellen verwenden eine Tabelle und Datenvorbereitung 🎜#

      Update
      -- 这里定义了bit(3),表示有3位,第一位1,第二位2,第三位4
      create table t_bit_demo(
         id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
         multi_value bit(3) not null default 0
      );
      
      -- 这里插入了1,2,4的组合值
      insert into t_bit_demo(multi_value) values(b'000');
      insert into t_bit_demo(multi_value) values(b'001');
      insert into t_bit_demo(multi_value) values(b'010');
      insert into t_bit_demo(multi_value) values(b'011');
      insert into t_bit_demo(multi_value) values(b'100');
      insert into t_bit_demo(multi_value) values(b'101');
      insert into t_bit_demo(multi_value) values(b'110');
      insert into t_bit_demo(multi_value) values(b'111');
      
      -- 这里直接插入int值也可以,比如5相当于101
      -- insert into t_bit_demo(multi_value) values(5);
      
      SELECT multi_value+0, BIN(multi_value) FROM t_bit_demo;
      +---------------+------------------+
      | multi_value+0 | BIN(multi_value) |
      +---------------+------------------+
      | 0             | 0                |
      | 1             | 1                |
      | 2             | 10               |
      | 3             | 11               |
      | 4             | 100              |
      | 5             | 101              |
      | 6             | 110              |
      | 7             | 111              |
      +---------------+------------------+
    • Typ int/bigint verwenden

    Tabellen erstellen und Daten vorbereiten. 🎜##🎜 🎜 #Update
    • -- 查询第二位有值的数据
      select multi_value+0,BIN(multi_value) from t_bit_demo where multi_value & 2
      +---------------+------------------+
      | multi_value+0 | BIN(multi_value) |
      +---------------+------------------+
      | 2             | 10               |
      | 3             | 11               |
      | 6             | 110              |
      | 7             | 111              |
      +---------------+------------------+
      
      -- 查询第三位有值的数据
      select multi_value+0,BIN(multi_value) from t_bit_demo where multi_value & 4
      +---------------+------------------+
      | multi_value+0 | BIN(multi_value) |
      +---------------+------------------+
      | 4             | 100              |
      | 5             | 101              |
      | 6             | 110              |
      | 7             | 111              |
      +---------------+------------------+
      
      -- 查询只有第三位有值的数据
      select multi_value+0,BIN(multi_value) from t_bit_demo where multi_value = 4
      select multi_value+0,BIN(multi_value) from t_bit_demo where multi_value = 4
      +---------------+------------------+
      | multi_value+0 | BIN(multi_value) |
      +---------------+------------------+
      | 4             | 100              |
      +---------------+------------------+

      Varchar-Typ verwenden

    Tabellenerstellung und Datenvorbereitung#🎜 🎜##🎜🎜 #
      select id,multi_value+0,BIN(multi_value) from t_bit_demo
      +----+---------------+------------------+
      | id | multi_value+0 | BIN(multi_value) |
      +----+---------------+------------------+
      | 1  | 0             | 0                |
      | 2  | 1             | 1                |
      | 3  | 2             | 10               |
      | 4  | 3             | 11               |
      | 5  | 4             | 100              |
      | 6  | 5             | 101              |
      | 7  | 6             | 110              |
      | 8  | 7             | 111              |
      +----+---------------+------------------+
      
      -- 将id为7的值移除第二个枚举
      update t_bit_demo set multi_value = b'100' where id=7
      select id,multi_value+0,BIN(multi_value) from t_bit_demo where id=7
      +----+---------------+------------------+
      | id | multi_value+0 | BIN(multi_value) |
      +----+---------------+------------------+
      | 7  | 4             | 100              |
      +----+---------------+------------------+
    • query
      create table t_bigint_demo(
         id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
         multi_value bigint not null default 0
      );
      
      -- 假设这里定义了1,2,4三个枚举值
      insert into t_bigint_demo(multi_value) values(0);
      insert into t_bigint_demo(multi_value) values(1);
      insert into t_bigint_demo(multi_value) values(2);
      insert into t_bigint_demo(multi_value) values(3);
      insert into t_bigint_demo(multi_value) values(4);
      insert into t_bigint_demo(multi_value) values(5);
      insert into t_bigint_demo(multi_value) values(6);
      insert into t_bigint_demo(multi_value) values(7);
      
      select multi_value from t_bigint_demo
      +-------------+
      | multi_value |
      +-------------+
      | 0           |
      | 1           |
      | 2           |
      | 3           |
      | 4           |
      | 5           |
      | 6           |
      | 7           |
      +-------------+
    • # 🎜🎜#Update

      # 🎜🎜#
    • -- 查询包含第二个枚举的数据
      select multi_value,BIN(multi_value) from t_bigint_demo where multi_value & 2
      +-------------+------------------+
      | multi_value | BIN(multi_value) |
      +-------------+------------------+
      | 2           | 10               |
      | 3           | 11               |
      | 6           | 110              |
      | 7           | 111              |
      +-------------+------------------+
      
      -- 查询包含第三个枚举的数据
      select multi_value,BIN(multi_value) from t_bigint_demo where multi_value & 4
      +-------------+------------------+
      | multi_value | BIN(multi_value) |
      +-------------+------------------+
      | 4           | 100              |
      | 5           | 101              |
      | 6           | 110              |
      | 7           | 111              |
      +-------------+------------------+
      
      -- 查询值为第三个枚举的数据
      select multi_value,BIN(multi_value) from t_bigint_demo where multi_value =4
      +-------------+------------------+
      | multi_value | BIN(multi_value) |
      +-------------+------------------+
      | 4           | 100              |
      +-------------+------------------+
    Set-Typ verwenden
    • Tabellen erstellen und Daten vorbereiten
    # 🎜🎜#
    select id,multi_value,BIN(multi_value) from t_bigint_demo
    +----+-------------+------------------+
    | id | multi_value | BIN(multi_value) |
    +----+-------------+------------------+
    | 1  | 0           | 0                |
    | 2  | 1           | 1                |
    | 3  | 2           | 10               |
    | 4  | 3           | 11               |
    | 5  | 4           | 100              |
    | 6  | 5           | 101              |
    | 7  | 6           | 110              |
    | 8  | 7           | 111              |
    +----+-------------+------------------+
    
    -- 将id为7的值移除第二个枚举
    update t_bigint_demo set multi_value = b'100' where id=7
    select id,multi_value,BIN(multi_value) from t_bigint_demo where id=7
    +----+-------------+------------------+
    | id | multi_value | BIN(multi_value) |
    +----+-------------+------------------+
    | 7  | 4           | 100              |
    +----+-------------+------------------+
    # 🎜🎜#

    Query
    • create table t_varchar_demo(
         id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
         multi_value varchar(255) not null default ''
      );
      
      -- 假设这里定义了1,2,4三个枚举值
      insert into t_varchar_demo(multi_value) values('1');
      insert into t_varchar_demo(multi_value) values('2');
      insert into t_varchar_demo(multi_value) values('1,2');
      insert into t_varchar_demo(multi_value) values('4');
      insert into t_varchar_demo(multi_value) values('1,4');
      insert into t_varchar_demo(multi_value) values('2,4');
      insert into t_varchar_demo(multi_value) values('1,2,4');
      
      select multi_value from t_varchar_demo
      +-------------+
      | multi_value |
      +-------------+
      | 1           |
      | 2           |
      | 1,2         |
      | 4           |
      | 1,4         |
      | 2,4         |
      | 1,2,4       |
      +-------------+

    Update#🎜 🎜##🎜🎜 ##🎜 🎜#
    -- 查询包含第二个枚举的数据
    select multi_value from t_varchar_demo where find_in_set('2',multi_value)
    +-------------+
    | multi_value |
    +-------------+
    | 2           |
    | 1,2         |
    | 2,4         |
    | 1,2,4       |
    +-------------+
    
    -- 查询包含第三个枚举的数据
    select multi_value from t_varchar_demo where find_in_set('4',multi_value)
    +-------------+
    | multi_value |
    +-------------+
    | 4           |
    | 1,4         |
    | 2,4         |
    | 1,2,4       |
    +-------------+
    
    -- 查询只有第三个枚举的数据
    select multi_value from t_varchar_demo where multi_value = '4'
    +-------------+
    | multi_value |
    +-------------+
    | 4           |
    +-------------+

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