SQLite 只有 5 种数据类型:NULL 、INTEGER 、REAL 、TEXT 、BLOB,你所定义的其它类型都被转到这 5 种类型最终存储。 SQLite 中类型定义的括号中的数字是会被忽略的。( Note that numeric arguments in parentheses that following the type name (ex: "VARCHAR(255)") are ignored by SQLite - SQLite does not impose any length restrictions (other than the large global SQLITE_MAX_LENGTH limit) on the length of strings, BLOBs or numeric values.)