SQLite で変数をシミュレートするにはどうすればよいですか?

<code class="language-sql">BEGIN; /* 开始事务 */

PRAGMA temp_store = 2; /* 使用内存模式创建临时表 */
CREATE TEMP TABLE _Variables(
  Name TEXT PRIMARY KEY,
  RealValue REAL,
  IntegerValue INTEGER,
  BlobValue BLOB,
  TextValue TEXT
);</code>

<code class="language-sql">INSERT INTO _Variables (Name) VALUES ('VariableName');</code>

<code class="language-sql">UPDATE _Variables SET IntegerValue = ... WHERE Name = 'VariableName';</code>

<code class="language-sql">... (
  SELECT COALESCE(RealValue, IntegerValue, BlobValue, TextValue)
  FROM _Variables
  WHERE Name = 'VariableName'
  LIMIT 1
) ...</code>

<code class="language-sql">DROP TABLE _Variables;
END; /* 结束事务 */</code>