Платформа ЦРНП "Мирокод" для разработки проектов
https://git.mirocod.ru
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
135 lines
3.6 KiB
135 lines
3.6 KiB
/* |
|
Package sqlite3 provides interface to SQLite3 databases. |
|
|
|
This works as a driver for database/sql. |
|
|
|
Installation |
|
|
|
go get github.com/mattn/go-sqlite3 |
|
|
|
Supported Types |
|
|
|
Currently, go-sqlite3 supports the following data types. |
|
|
|
+------------------------------+ |
|
|go | sqlite3 | |
|
|----------|-------------------| |
|
|nil | null | |
|
|int | integer | |
|
|int64 | integer | |
|
|float64 | float | |
|
|bool | integer | |
|
|[]byte | blob | |
|
|string | text | |
|
|time.Time | timestamp/datetime| |
|
+------------------------------+ |
|
|
|
SQLite3 Extension |
|
|
|
You can write your own extension module for sqlite3. For example, below is an |
|
extension for a Regexp matcher operation. |
|
|
|
#include <pcre.h> |
|
#include <string.h> |
|
#include <stdio.h> |
|
#include <sqlite3ext.h> |
|
|
|
SQLITE_EXTENSION_INIT1 |
|
static void regexp_func(sqlite3_context *context, int argc, sqlite3_value **argv) { |
|
if (argc >= 2) { |
|
const char *target = (const char *)sqlite3_value_text(argv[1]); |
|
const char *pattern = (const char *)sqlite3_value_text(argv[0]); |
|
const char* errstr = NULL; |
|
int erroff = 0; |
|
int vec[500]; |
|
int n, rc; |
|
pcre* re = pcre_compile(pattern, 0, &errstr, &erroff, NULL); |
|
rc = pcre_exec(re, NULL, target, strlen(target), 0, 0, vec, 500); |
|
if (rc <= 0) { |
|
sqlite3_result_error(context, errstr, 0); |
|
return; |
|
} |
|
sqlite3_result_int(context, 1); |
|
} |
|
} |
|
|
|
#ifdef _WIN32 |
|
__declspec(dllexport) |
|
#endif |
|
int sqlite3_extension_init(sqlite3 *db, char **errmsg, |
|
const sqlite3_api_routines *api) { |
|
SQLITE_EXTENSION_INIT2(api); |
|
return sqlite3_create_function(db, "regexp", 2, SQLITE_UTF8, |
|
(void*)db, regexp_func, NULL, NULL); |
|
} |
|
|
|
It needs to be built as a so/dll shared library. And you need to register |
|
the extension module like below. |
|
|
|
sql.Register("sqlite3_with_extensions", |
|
&sqlite3.SQLiteDriver{ |
|
Extensions: []string{ |
|
"sqlite3_mod_regexp", |
|
}, |
|
}) |
|
|
|
Then, you can use this extension. |
|
|
|
rows, err := db.Query("select text from mytable where name regexp '^golang'") |
|
|
|
Connection Hook |
|
|
|
You can hook and inject your code when the connection is established by setting |
|
ConnectHook to get the SQLiteConn. |
|
|
|
sql.Register("sqlite3_with_hook_example", |
|
&sqlite3.SQLiteDriver{ |
|
ConnectHook: func(conn *sqlite3.SQLiteConn) error { |
|
sqlite3conn = append(sqlite3conn, conn) |
|
return nil |
|
}, |
|
}) |
|
|
|
You can also use database/sql.Conn.Raw (Go >= 1.13): |
|
|
|
conn, err := db.Conn(context.Background()) |
|
// if err != nil { ... } |
|
defer conn.Close() |
|
err = conn.Raw(func (driverConn interface{}) error { |
|
sqliteConn := driverConn.(*sqlite3.SQLiteConn) |
|
// ... use sqliteConn |
|
}) |
|
// if err != nil { ... } |
|
|
|
Go SQlite3 Extensions |
|
|
|
If you want to register Go functions as SQLite extension functions |
|
you can make a custom driver by calling RegisterFunction from |
|
ConnectHook. |
|
|
|
regex = func(re, s string) (bool, error) { |
|
return regexp.MatchString(re, s) |
|
} |
|
sql.Register("sqlite3_extended", |
|
&sqlite3.SQLiteDriver{ |
|
ConnectHook: func(conn *sqlite3.SQLiteConn) error { |
|
return conn.RegisterFunc("regexp", regex, true) |
|
}, |
|
}) |
|
|
|
You can then use the custom driver by passing its name to sql.Open. |
|
|
|
var i int |
|
conn, err := sql.Open("sqlite3_extended", "./foo.db") |
|
if err != nil { |
|
panic(err) |
|
} |
|
err = db.QueryRow(`SELECT regexp("foo.*", "seafood")`).Scan(&i) |
|
if err != nil { |
|
panic(err) |
|
} |
|
|
|
See the documentation of RegisterFunc for more details. |
|
|
|
*/ |
|
package sqlite3
|
|
|