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app/src/main/java/com/hippo/util/SqlUtils.java

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+/*
+ * Copyright 2016 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.util;
+
+import android.database.Cursor;
+import android.database.SQLException;
+import android.database.sqlite.SQLiteDatabase;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class SqlUtils {
+
+    public static void exeSQLSafely(SQLiteDatabase db, String sql) {
+        try {
+            db.execSQL(sql);
+        } catch (SQLException e) {
+            // Ignore
+        }
+    }
+
+    public static void dropTable(SQLiteDatabase db, String tableName) {
+        exeSQLSafely(db, "DROP TABLE IF EXISTS " + tableName);
+    }
+
+    public static void dropAllTable(SQLiteDatabase db) {
+        List<String> tables = new ArrayList<String>();
+        Cursor cursor = db.rawQuery("SELECT * FROM sqlite_master WHERE type='table';", null);
+        cursor.moveToFirst();
+        while (!cursor.isAfterLast()) {
+            String tableName = cursor.getString(1);
+            if (!tableName.equals("android_metadata") &&
+                    !tableName.equals("sqlite_sequence"))
+                tables.add(tableName);
+            cursor.moveToNext();
+        }
+        cursor.close();
+
+        for(String tableName : tables) {
+            dropTable(db, tableName);
+        }
+    }
+}