1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/*
* Copyright (C) 2013 The Android Open Source Project
*
* 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.android.providers.contacts.database;
/**
* Static methods for database operations.
*/
public class MoreDatabaseUtils {
/**
* Builds a CREATE INDEX ddl statement for a given table and field.
*
* @param table The table name.
* @param field The field to index.
* @return The create index sql statement.
*/
public static String buildCreateIndexSql(String table, String field) {
return "CREATE INDEX " + buildIndexName(table, field) + " ON " + table
+ "(" + field + ")";
}
/**
* Builds a DROP INDEX ddl statement for a given table and field.
*
* @param table The table name that was originally used to create the index.
* @param field The field that was originally used to create the index.
* @return The drop index sql statement.
*/
public static String buildDropIndexSql(String table, String field) {
return "DROP INDEX IF EXISTS " + buildIndexName(table, field);
}
/**
* The index is created with a name using the following convention:
* <p>
* [table name]_[field name]_index
*/
public static String buildIndexName(String table, String field) {
return table + "_" + field + "_index";
}
/**
* Build a bind arg where clause.
* <p>
* e.g. Calling this method with value of 4 results in:
* <p>
* "?,?,?,?"
*
* @param numArgs The number of arguments.
* @return A string that can be used for bind args in a sql where clause.
*/
public static String buildBindArgString(int numArgs) {
final StringBuilder sb = new StringBuilder();
String delimiter = "";
for (int i = 0; i < numArgs; i++) {
sb.append(delimiter).append("?");
delimiter = ",";
}
return sb.toString();
}
}
|
