Built-In Scalar SQL Functions (sqlite.org)
2 初始化分配系统(其实里面没做什么)sqlite3MallocInit 3 初始化内建方法sqlite3RegisterBuiltinFunctions 4 初始化PCache系统sqlite3PcacheInitialize 5 初始化os子系统sqlite3OsInit,其中初始化了vfs子系统sqlite3_vfs_register 6 初始化了内存数据库sqlite3MemdbInit 7 PCache系统创建sqlite3PCacheBufferSetup 而他们...
Built-in date and time functions Custom formulas have built-in functions that you can also use to modify dates and times. Some of those include: DATEADD(date_string, amount, 'unit') Adds a time interval to a date or datetme DATESUB(date_string, amount, 'unit') Subtracts a time interv...
3.6.4、记录函数(Record Functions) sqlite3BtreeDelete: Deletes the record that the cursorispointing to.sqlite3BtreeInsert: Inserts anewelementinthe appropriate place of the B-tree.sqlite3BtreeKeySize: Returns the number of bytesinthe key of the record that the cursorispointing to.sqlite3BtreeKey...
2. Simplicity:Built-in functions make it easy to work with dates without external libraries. 3. Portability:Compatible across platforms due to SQLite's lightweight nature. 4. Powerful Arithmetic:Supports adding, subtracting, and comparing dates. ...
Mathematical SQL Functions – The following mathematical SQL functions are available in addition to the SQLite default: ACOS(), ASIN(), ATAN(), ATAN(), ATAN2(), CEIL(), CEILING(), COS(), COT(), DEGREES(), EXP(), FLOOR(), LN(), LOG(), LOG(), LOG2(), LOG10(), MOD(), PI...
It is not necessary for every column of an index to appear in a WHERE clause term in order for that index to be used. But there can not be gaps in the columns of the index that are used. Thus for the example index above, if there is no WHERE clause term that constraints column c...
Individual values (strings, integer, floating point numbers, and BLOBs) are stored in an internal object named "Mem" which is implemented by vdbemem.c. SQLite implements SQL functions using callbacks to C-language routines. Even the built-in SQL functions are implemented this way. Most of the...
-- 创建存储过程(SQLite 不直接支持存储过程,但可以通过创建包含多个SQL语句的脚本来模拟) CREATE PROCEDURE get_user(IN user_id INTEGER) BEGIN SELECT * FROM users WHERE id = user_id; END; -- 调用存储过程 CALL get_user(1); -- 删除存储过程 DROP PROCEDURE get_user; 创建和管理用户定义函数 用户...
The core functions shown below are available by default. Date & Time functions, aggregate functions, and JSON functions are documented separately. An application may define additional functions written in C and added to the database engine using the sqlite3_create_function() API....