[代码实例][C语言][sqlite3]用SQL语句查询数据库的实例

下载sqlite3源代码

---

https://www.sqlite.org/

编译安装sqlite3的Makefile

---

INSTALL_PATH    =/usr/local

all: install

libsqlite3.so: sqlite3.c sqlite3.h
    gcc -shared -fPIC $< -o $@

install_lib: libsqlite3.so install_headers
    cp libsqlite3.so $(INSTALL_PATH)/lib
    ldconfig $(INSTALL_PATH)/lib

install_headers: sqlite3.h sqlite3ext.h
    cp $^ $(INSTALL_PATH)/include/

sqlite3: install_lib shell.c
    $(CC) shell.c -o $@ -lsqlite3 -lpthread -ldl

install_shell: sqlite3
    cp $^ $(INSTALL_PATH)/bin

install: install_lib install_shell

uninstall:
    rm -f \
        $(INSTALL_PATH)/lib/libsqlite3.so \
        $(INSTALL_PATH)/include/sqlite3.h \
        $(INSTALL_PATH)/include/sqlite3ext.h \
        $(INSTALL_PATH)/bin/sqlite3

clean:
    rm -f *.so sqlite3

.PHONY: install install_lib install_headers install_shell clean

客户端程序

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/*
 * main.c
 */
#include 
#include 
#include 

static int callback(void * not_used, int argc, char * argv[], char * col_names[]);

int main(int argc, char * argv[])
{
    sqlite3 * db = NULL;
    char * zErrMsg = NULL;

    if(argc != 3)
    {
        fprintf(stderr, "Usage: %s DATABASE SQL-STATEMENT\n", argv[0]);
        return EXIT_FAILURE;
    }

    if(sqlite3_open(argv[1], &db) != SQLITE_OK)
    {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return EXIT_FAILURE;
    }

    if(sqlite3_exec(db, argv[2], callback, NULL, &zErrMsg) != SQLITE_OK)
    {
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    }

    sqlite3_close(db);

    return EXIT_SUCCESS;
}

static int callback(void * not_used, int argc, char * argv[], char * col_names[])
{
    for(int i; i < argc; i++)
        printf("%s = %s\n", col_names[i], argv[i] ? argv[i] : "NULL");
    printf("\n");
    return 0;
}

编译客户端程序的Makefile

---

all: main

main: main.c
    gcc main.c -o main -lsqlite3 -lpthread -ldl

clean:
    rm -r main

.PHONY: clean

数据库脚本文件

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/*
 * test.sql
 */

DROP TABLE main.user;
CREATE TABLE main.user(
   Name TEXT,
   Age INTEGER
);

INSERT INTO user VALUES('Huo Yun', 27);
INSERT INTO user VALUES('Gao Jingzhuo', 30);