使用 RANK() 创建 View 的 Android SQLite 语法错误

Question

我正在尝试使用 RANK() 窗口函数在 SQLite 中创建一个 View 。当我执行以下代码时:

val txt = "CREATE VIEW VW_CAPITULOS_ORDER AS\n" +
          "    SELECT id_libro, capitulo,\n" +
          "            RANK() OVER (\n" +
          "                ORDER BY id_libro, CAST(SUBSTR(capitulo, 1, INSTR(capitulo||' ', ' ')) AS INTEGER)\n" +
          "                ) ranking\n" +
          "        FROM tbl_capitulos;\n"

db.execSQL(txt)

在运行时，我收到以下异常:

*E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.systango.bibliacatolica, PID: 20837
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.systango.bibliacatolica/com.systango.bibliacatolica.MainActivity}: android.database.sqlite.SQLiteException: near "(": syntax error (Sqlite code 1 SQLITE_ERROR): , while compiling: CREATE VIEW VW_CAPITULOS_ORDER AS
        SELECT id_libro, capitulo,
                RANK() OVER (
                    ORDER BY id_libro, CAST(SUBSTR(capitulo, 1, INSTR(capitulo||' ', ' ')) AS INTEGER)
                    ) ranking
            FROM tbl_capitulos;, (OS error - 11:Try again)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3897)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4076)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2473)
        at android.os.Handler.dispatchMessage(Handler.java:110)
        at android.os.Looper.loop(Looper.java:219)
        at android.app.ActivityThread.main(ActivityThread.java:8349)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1055)
     Caused by: android.database.sqlite.SQLiteException: near "(": syntax error (Sqlite code 1 SQLITE_ERROR): , while compiling: CREATE VIEW VW_CAPITULOS_ORDER AS
        SELECT id_libro, capitulo,
                RANK() OVER (
                    ORDER BY id_libro, CAST(SUBSTR(capitulo, 1, INSTR(capitulo||' ', ' ')) AS INTEGER)
                    ) ranking
            FROM tbl_capitulos;, (OS error - 11:Try again)
        at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
        at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1030)
        at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:637)
        at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:610)
        at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:66)
        at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:33)
        at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1899)
        at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1817)*

我怀疑这是 Android 中存在的 SQLite 版本(在华为 P40 Lite 上检查版本 3.22)或类似问题。 SQLite 文档说窗口函数出现在 3.25 版( https://sqlite.org/windowfunctions.html )中。这个脚本在 DB Browser for SQLite 中执行没有问题应用程序。有没有办法使用新版本的 SQLite 那个手机自带的版本？

Answer 1

您的应用无法更改您手机的 SQLite 版本。
作为一种解决方法，您可以使用相关子查询来模仿窗口函数的功能 RANK() :

CREATE VIEW VW_CAPITULOS_ORDER AS
SELECT c.id_libro, c.capitulo,
       (
         SELECT COUNT(*) FROM tbl_capitulos 
         WHERE id_libro < c.id_libro 
            OR (id_libro = c.id_libro AND (capitulo + 0) < (c.capitulo + 0))
       ) + 1 ranking
FROM tbl_capitulos c;

请注意，您不需要取 capitulo 的子字符串直到第一个 ' '以便将其转换为整数。
您可以通过添加 0 来进行隐式转换.