DbQueryUtils.java revision aafbe295d67686870c64c74a59e589d1dfb506fa 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License
15 */
16package com.android.providers.contacts.util;
17
18import android.content.ContentValues;
19import android.database.DatabaseUtils;
20import android.text.TextUtils;
21
22import java.util.HashMap;
23
24/**
25 * Static methods for helping us build database query selection strings.
26 */
27public class DbQueryUtils {
28    // Static class with helper methods, so private constructor.
29    private DbQueryUtils() {
30    }
31
32    /** Returns a WHERE clause asserting equality of a field to a value. */
33    public static String getEqualityClause(String field, String value) {
34        return getClauseWithOperator(field, "=", value);
35    }
36
37    /** Returns a WHERE clause asserting in-equality of a field to a value. */
38    public static String getInequalityClause(String field, String value) {
39        return getClauseWithOperator(field, "!=", value);
40    }
41
42    private static String getClauseWithOperator(String field, String operator, String value) {
43        StringBuilder clause = new StringBuilder();
44        clause.append("(");
45        clause.append(field);
46        clause.append(" ").append(operator).append(" ");
47        DatabaseUtils.appendEscapedSQLString(clause, value);
48        clause.append(")");
49        return clause.toString();
50    }
51
52    /** Concatenates any number of clauses using "AND". */
53    public static String concatenateClauses(String... clauses) {
54        StringBuilder builder = new StringBuilder();
55        for (String clause : clauses) {
56            if (!TextUtils.isEmpty(clause)) {
57                if (builder.length() > 0) {
58                    builder.append(" AND ");
59                }
60                builder.append("(");
61                builder.append(clause);
62                builder.append(")");
63            }
64        }
65        return builder.toString();
66    }
67
68    /**
69     * Checks if the given ContentValues contains values within the projection
70     * map.
71     * @throws IllegalArgumentException if any value in values is not found in
72     * the projection map.
73     */
74    public static void checkForSupportedColumns(HashMap<String, String> projectionMap,
75            ContentValues values) {
76        for (String requestedColumn : values.keySet()) {
77            if (!projectionMap.keySet().contains(requestedColumn)) {
78                throw new IllegalArgumentException("Column '" + requestedColumn + "' is invalid.");
79            }
80        }
81    }
82}
83