从这里Create Or Redefine SQL Functions可以看出: The first parameter is thedatabase connectionto which the SQL function is to be added. If an application uses more than one database connection then application-defined SQL functions must be added to each database connection separately. 需要为每个数...
Built-in functions may be overloaded by new application-defined functions. An application-defined function is permitted to call other SQLite interfaces. However, such calls must not close the database connection nor finalize or reset the prepared statement in which the function is running....
sqlite3_config()允许程序员做以下的事情: 调整SQLite 如何分配内存,包括为安全敏感(safety-critical)的实时的嵌入式系统和应用程序定义的(application-defined)内存分配器设置为可选的(alternative)内存分配器(memory allocators)。 设置一个进程级的错误日志。 指定一个应用程序定义的页缓存(page cache)。 调整 mutex...
Allow read transactions to be freely opened and closed by SQL statements run from within the implementation ofapplication-defined SQL functionsif the function is called by a SELECT statement that does not access any database table. Disable the use of posix_fallocate() on all (unix) systems unle...
hash_functions (bool)– Make hashing functions available (md5, sha1, etc). regexp_function (bool)– Make the REGEXP function available. bloomfilter (bool)– Make the bloom filter available. Extends SqliteDatabase and inherits methods for declaring user-defined functions, pragmas, etc.class...
大多数数据库都具有 SQL 的过程方言,用户可以使用它定义自己的函数。 但是,SQLite 将在你的应用的进程内运行。 无需学习新的 SQL 方言,只需使用应用的编程语言即可。 标量函数 标量函数为查询中的每一行返回单个标量值。 定义新的标量函数,并使用CreateFunction覆盖内置函数。
Intricate SQLite schema elements like foreign keys, triggers, or user-defined functions may not be accurately translated by the ODBC driver. This may lead to inconsistencies in the target SQL databases. ODBC Driver does basic data transformations but lacks in dealing with complex data structures....
Multi-threading support is low-priority and untested. If your application-defined functions and virtual tables don't reference data outside of the database they are attached to, this will not cause issues because SQLite always does database operations in a single thread. However, the API needs...
The SQLite interface is defined by thesqlite3.hheader file, which is generated from src/sqlite.h.in, ./manifest.uuid, and ./VERSION. TheTcl scriptat tool/mksqlite3h.tcl does the conversion. The manifest.uuid file contains the SHA3 hash of the particular check-in and is used to generat...
Add the ability forapplication-defined SQL functionsto have the same name as join keywords: CROSS,...