如何使用Android NDK SQLite3 扩展json1

Question

不好意思我先缺英文

我编译它是因为我需要 Android NDK

中的 SQLite3 扩展 JSON1

gcc -Os -I. -DSQLITE_THREADSAFE=0     -DSQLITE_ENABLE_JSON1             \
   -DSQLITE_DEFAULT_MEMSTATUS=0       -DSQLITE_USE_ALLOCA               \
   -DSQLITE_DEFAULT_WAL_SYNCHRONOUS=1 -DSQLITE_LIKE_DOESNT_MATCH_BLOBS  \
   -DSQLITE_MAX_EXPR_DEPTH=0          -DSQLITE_OMIT_DECLTYPE            \
   -DSQLITE_OMIT_PROGRESS_CALLBACK    -DSQLITE_OMIT_SHARED_CACHE        \
   -DSQLITE_OMIT_DEPRECATED           -DHAVE_USLEEP     -DHAVE_READLINE \
   shell.c sqlite3.c -ldl -lreadline -lncurses -o sqlite3

编译结果为sqlite3.exe

如何将此文件用于 Anroid NDK 或者我可以找到其他方法吗？

我要使用的代码

JNIEXPORT void JNICALL
Java_com_test_ndkapp_MainActivity_SQLiteCPP(
        JNIEnv *jenv,
        jobject self,
        jstring database_path
){
    sqlite3 *db;
    sqlite3_stmt *stmt;

    // jstring to const char *
    const char *database = jenv->GetStringUTFChars(database_path, 0);

    char *zErrMsg = 0;
    int rc;

    //SQL ERROR:no such function: json
    const char * create_sql = "create table user(name, phone)";
    const char * insert_sql = "insert into user (name, phone) values(\"oz\", json('{\"cell\":\"+491765\", \"home\":\"+498973\"}'))";
    const char * select_sql = "select json_extract(user.phone, '$.cell') from user";

    if (sqlite3_open_v2(database, &db, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE , NULL) == SQLITE_OK) {
        LOGE("database open!!");

        rc = sqlite3_exec(db, create_sql, NULL, NULL, &zErrMsg);

        if( rc != SQLITE_OK ) {
            LOGE("SQL ERROR:%s", zErrMsg);
            sqlite3_free(zErrMsg);
        } else {
            LOGE("CREATE Operation done successfully\n");
        }

        rc = sqlite3_exec(db, insert_sql, NULL, NULL, &zErrMsg);

        if( rc != SQLITE_OK ) {
            LOGE("SQL ERROR:%s", zErrMsg);
            sqlite3_free(zErrMsg);
        } else {
            LOGE("INSERT Operation done successfully\n");
        }

        rc = sqlite3_prepare_v2(db, select_sql, -1, &stmt, NULL);

        if( rc != SQLITE_OK ) {
            LOGE("SQL ERROR:%s", zErrMsg);
            sqlite3_free(zErrMsg);
        } else {
            while ((rc = sqlite3_step(stmt)) == SQLITE_ROW) {
                const unsigned char * aaa           = sqlite3_column_text (stmt, 0);
                const unsigned char * bbb           = sqlite3_column_text (stmt, 1);

                LOGE("%s, %s", aaa, bbb);
            }

            if (rc != SQLITE_DONE) {
                LOGE("error: %s", sqlite3_errmsg(db));
            }

            LOGE("SELECT Operation done successfully\n");

            sqlite3_finalize(stmt);
        }

    } else {
        LOGE("database can not open!! : %s", sqlite3_errmsg(db));
    }

    sqlite3_close(db);
}

我试过了
只需将 .c 文件和 .h 文件放在 cpp 文件夹中 → SQLite3 可以工作但没有这样的功能 json

Answer 1

您需要 libsqlite3，而不是可执行文件，因此您不需要编译 shell.c。在您的 JNI 项目中有一个 GitHub project that includes the Android.mk that creates such library for you, you will probably find the static library 更易于使用。

Answer 2

如果您在 AndroidStudio 中开发 NDK，我发现如何通过在使用 CMakeLists 的环境中添加一个标志来使用 JSON1。

首先，下载sqlite-amalgamation-(你要的版本).zip
并解压 .zip 文件
https://www.sqlite.org/download.html（下载 link）

将获取到的4个文件放在项目的cpp目录下的指定路径下。

The path to the file that I used

然后将代码添加到 CMakeList.txt。

add_library( # Sets the name of the library.
         native-lib

         # Sets the library as a shared library.
         SHARED

         # Provides a relative path to your source file(s).
         src/main/cpp/native-lib.cpp
         src/main/cpp/sqlite/shell.c
         src/main/cpp/sqlite/sqlite3.c
         src/main/cpp/sqlite/sqlite3.h
         src/main/cpp/sqlite/sqlite3ext.h
    )

....

add_definitions( -DSQLITE_ENABLE_JSON1 )

现在可以使用SQLite3的JSON1函数了

const char * create_sql = "create table user(name, phone)";
const char * insert_sql = "insert into user (name, phone) values(\"oz\", json('{\"cell\":\"+491765\", \"home\":\"+498973\"}'))";
const char * select_sql = "select json_extract(user.phone, '$.cell') from user";

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