golang通过mattn/go-sqlite3访问BDB

golang通过mattn/go-sqlite3访问BDB

依赖包

1. BDB运行环境

$ tree -L 1 bdb 
bdb
|-- bin
|-- docs
|-- include
|-- lib
`-- share

2. mattn/go-sqlite3库

$ export GOPATH=$(pwd)
$ go get mattn/go-sqlite3
$ ls -l src/github.com/mattn/go-sqlite3

主程序

package main

import (
    "fmt"
    "log"
    "database/sql"

    "github.com/mattn/go-sqlite3"
)

func main() {     
    sqlDriver  := "sqlite3_with_extensions"
    fullDBPath := "data/test.db"
    
    sql.Register("sqlite3_with_extensions",                                                                                                                             
        &sqlite3.SQLiteDriver{
            Extensions: []string{
                "sqlite3_mod_regexp",
        },
    })

    // Open database
    db, err := sql.Open(sqlDriver, fullDBPath)
    if err != nil {
        log.Fatal(err)
    }
     
    // Exec
    db.SetMaxIdleConns(200)
    db.SetMaxOpenConns(200)
    _, err = db.Exec("PRAGMA page_size = 8192; PRAGMA synchronous = normal;")
    if err != nil {
        db.Close()
        log.Fatal(err)
    }
         
    // Query
    rows, err := db.Query("select key, value from mytable")
    if err != nil {
        db.Close()
        log.Fatal(err)
    }    
    defer rows.Close()
    for rows.Next() {
        var key string 
        var value string
        err = rows.Scan(&key, &value)
        if err != nil {
            db.Close()
            log.Fatal(err)
        }  
        fmt.Println(key, value)
    }    
    err = rows.Err()
    if err != nil {
        db.Close()
        log.Fatal(err)
    }

    db.Close()
}

Makefile文件

all: testbdb
     
testbdb: main.go
    LIBRARY_PATH=$(abspath bdb/lib) \
    LD_LIBRARY_PATH=$(abspath bdb/lib) \
    LD_RUN_PATH=$(abspath bdb/lib) \
    C_INCLUDE_PATH=$(abspath bdb/include) \
    GOPATH=$(abspath .) \ 
    go build -tags "libsqlite3"
     
.PHONY: clean
clean:
    rm -f testbdb

编译完之后我们看：

$ ldd testbdb 
        linux-vdso.so.1 =>  (0x00007ffd4abd2000)
        libsqlite3.so => /fullpathto/bdb/lib/libsqlite3.so (0x00007f5b184af000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00007f5b18282000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f5b18066000)
        libc.so.6 => /lib64/libc.so.6 (0x00007f5b17c99000)
        /lib64/ld-linux-x86-64.so.2 (0x000055ba571b3000)

而如果我们编译的时候去掉-tags "libsqlite3"选项：

$ ldd testbdb 
        linux-vdso.so.1 =>  (0x00007ffcddfda000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00007f7945fb2000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f7945d95000)
        libc.so.6 => /lib64/libc.so.6 (0x00007f79459c8000)
        /lib64/ld-linux-x86-64.so.2 (0x000055b751f99000)

此时testbdb的动态链接库里面没有libsqlite3.so，因此此时采用的是静态连接方法。