相关疑难解决方法(0)

我有一个函数,它在SQLite数据库中的表上执行查询.我宣布一个常数:public static final String CANADA_HISTORY = "Canada's History";.这存储在一个String变量中,比方说difficulty,

我有一个问题:

Cursor c = mDb.rawQuery("select * from Questions_answers where CHAPTERS = '"+difficulty+"'" , null);

它在撇号附近抛出异常.

Logcat输出:

I/Database( 1170): sqlite returned: error code = 1, msg = near "s": syntax error
D/AndroidRuntime( 1170): Shutting down VM
W/dalvikvm( 1170): threadid=1: thread exiting with uncaught exception (group=0x40015560)
E/AndroidRuntime( 1170): FATAL EXCEPTION: main
E/AndroidRuntime( 1170): android.database.sqlite.SQLiteException: near "s": syntax error: , while compiling: select * from Questions_answers where CHAPTERS  = …

关于数据库查询的几个问题:

所以我有以下数据库查询,它有一个WHERE语句,其中包含三个String变量(rackingSystem,制造商,"Amber Risk").

public Cursor fetchComponentsAndSpecForManufacturer(long inspectionId, String rackingSystem, String manufacturer) {
    Cursor mCursor =
            rmDb.query(true, DAMAGED_COMPONENTS_TABLE, new String[] {
                    DAMAGED_COMPONENT_ID,
                    LOCATION_LINK,
                    RUN_LINK,
                    AREA_LINK,
                    INSPECTION_LINK,
                    LOCATION_REF,
                    RACKING_SYSTEM,
                    COMPONENT,
                    COMPONENT_TYPE,
                    QUANTITY,
                    POSITION,
                    RISK,
                    ACTION_REQUIRED,
                    NOTES_GENERAL,
                    MANUFACTURER,
                    TEXT1,
                    TEXT2,
                    TEXT3,
                    TEXT4,
                    NOTES_SPEC,
                    SPEC_SAVED}, 
                    INSPECTION_LINK + " = " + inspectionId + " AND " + RACKING_SYSTEM + " = ? AND " + MANUFACTURER + " = ? AND " + RISK + " = ? ", 
                    new String[] {rackingSystem, manufacturer, "Amber …