| /* |
| * Copyright (C) 2006 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 android.database.sqlite; |
| |
| import android.database.Cursor; |
| import android.database.DatabaseUtils; |
| import android.provider.BaseColumns; |
| import android.text.TextUtils; |
| import android.util.Log; |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.Map.Entry; |
| import java.util.regex.Pattern; |
| |
| /** |
| * This is a convience class that helps build SQL queries to be sent to |
| * {@link SQLiteDatabase} objects. |
| */ |
| public class SQLiteQueryBuilder |
| { |
| private static final String TAG = "SQLiteQueryBuilder"; |
| private static final Pattern sLimitPattern = |
| Pattern.compile("\\s*\\d+\\s*(,\\s*\\d+\\s*)?"); |
| |
| private Map<String, String> mProjectionMap = null; |
| private String mTables = ""; |
| private final StringBuilder mWhereClause = new StringBuilder(64); |
| private boolean mDistinct; |
| private SQLiteDatabase.CursorFactory mFactory; |
| |
| public SQLiteQueryBuilder() { |
| mDistinct = false; |
| mFactory = null; |
| } |
| |
| /** |
| * Mark the query as DISTINCT. |
| * |
| * @param distinct if true the query is DISTINCT, otherwise it isn't |
| */ |
| public void setDistinct(boolean distinct) { |
| mDistinct = distinct; |
| } |
| |
| /** |
| * Returns the list of tables being queried |
| * |
| * @return the list of tables being queried |
| */ |
| public String getTables() { |
| return mTables; |
| } |
| |
| /** |
| * Sets the list of tables to query. Multiple tables can be specified to perform a join. |
| * For example: |
| * setTables("foo, bar") |
| * setTables("foo LEFT OUTER JOIN bar ON (foo.id = bar.foo_id)") |
| * |
| * @param inTables the list of tables to query on |
| */ |
| public void setTables(String inTables) { |
| mTables = inTables; |
| } |
| |
| /** |
| * Append a chunk to the WHERE clause of the query. All chunks appended are surrounded |
| * by parenthesis and ANDed with the selection passed to {@link #query}. The final |
| * WHERE clause looks like: |
| * |
| * WHERE (<append chunk 1><append chunk2>) AND (<query() selection parameter>) |
| * |
| * @param inWhere the chunk of text to append to the WHERE clause. |
| */ |
| public void appendWhere(CharSequence inWhere) { |
| if (mWhereClause.length() == 0) { |
| mWhereClause.append('('); |
| } |
| mWhereClause.append(inWhere); |
| } |
| |
| /** |
| * Append a chunk to the WHERE clause of the query. All chunks appended are surrounded |
| * by parenthesis and ANDed with the selection passed to {@link #query}. The final |
| * WHERE clause looks like: |
| * |
| * WHERE (<append chunk 1><append chunk2>) AND (<query() selection parameter>) |
| * |
| * @param inWhere the chunk of text to append to the WHERE clause. it will be escaped |
| * to avoid SQL injection attacks |
| */ |
| public void appendWhereEscapeString(String inWhere) { |
| if (mWhereClause.length() == 0) { |
| mWhereClause.append('('); |
| } |
| DatabaseUtils.appendEscapedSQLString(mWhereClause, inWhere); |
| } |
| |
| /** |
| * Sets the projection map for the query. The projection map maps |
| * from column names that the caller passes into query to database |
| * column names. This is useful for renaming columns as well as |
| * disambiguating column names when doing joins. For example you |
| * could map "name" to "people.name". If a projection map is set |
| * it must contain all column names the user may request, even if |
| * the key and value are the same. |
| * |
| * @param columnMap maps from the user column names to the database column names |
| */ |
| public void setProjectionMap(Map<String, String> columnMap) { |
| mProjectionMap = columnMap; |
| } |
| |
| /** |
| * Sets the cursor factory to be used for the query. You can use |
| * one factory for all queries on a database but it is normally |
| * easier to specify the factory when doing this query. @param |
| * factory the factor to use |
| */ |
| public void setCursorFactory(SQLiteDatabase.CursorFactory factory) { |
| mFactory = factory; |
| } |
| |
| /** |
| * Build an SQL query string from the given clauses. |
| * |
| * @param distinct true if you want each row to be unique, false otherwise. |
| * @param tables The table names to compile the query against. |
| * @param columns A list of which columns to return. Passing null will |
| * return all columns, which is discouraged to prevent reading |
| * data from storage that isn't going to be used. |
| * @param where A filter declaring which rows to return, formatted as an SQL |
| * WHERE clause (excluding the WHERE itself). Passing null will |
| * return all rows for the given URL. |
| * @param groupBy A filter declaring how to group rows, formatted as an SQL |
| * GROUP BY clause (excluding the GROUP BY itself). Passing null |
| * will cause the rows to not be grouped. |
| * @param having A filter declare which row groups to include in the cursor, |
| * if row grouping is being used, formatted as an SQL HAVING |
| * clause (excluding the HAVING itself). Passing null will cause |
| * all row groups to be included, and is required when row |
| * grouping is not being used. |
| * @param orderBy How to order the rows, formatted as an SQL ORDER BY clause |
| * (excluding the ORDER BY itself). Passing null will use the |
| * default sort order, which may be unordered. |
| * @param limit Limits the number of rows returned by the query, |
| * formatted as LIMIT clause. Passing null denotes no LIMIT clause. |
| * @return the SQL query string |
| */ |
| public static String buildQueryString( |
| boolean distinct, String tables, String[] columns, String where, |
| String groupBy, String having, String orderBy, String limit) { |
| if (TextUtils.isEmpty(groupBy) && !TextUtils.isEmpty(having)) { |
| throw new IllegalArgumentException( |
| "HAVING clauses are only permitted when using a groupBy clause"); |
| } |
| if (!TextUtils.isEmpty(limit) && !sLimitPattern.matcher(limit).matches()) { |
| throw new IllegalArgumentException("invalid LIMIT clauses:" + limit); |
| } |
| |
| StringBuilder query = new StringBuilder(120); |
| |
| query.append("SELECT "); |
| if (distinct) { |
| query.append("DISTINCT "); |
| } |
| if (columns != null && columns.length != 0) { |
| appendColumns(query, columns); |
| } else { |
| query.append("* "); |
| } |
| query.append("FROM "); |
| query.append(tables); |
| appendClause(query, " WHERE ", where); |
| appendClause(query, " GROUP BY ", groupBy); |
| appendClause(query, " HAVING ", having); |
| appendClause(query, " ORDER BY ", orderBy); |
| appendClause(query, " LIMIT ", limit); |
| |
| return query.toString(); |
| } |
| |
| private static void appendClause(StringBuilder s, String name, String clause) { |
| if (!TextUtils.isEmpty(clause)) { |
| s.append(name); |
| s.append(clause); |
| } |
| } |
| |
| private static void appendClauseEscapeClause(StringBuilder s, String name, String clause) { |
| if (!TextUtils.isEmpty(clause)) { |
| s.append(name); |
| DatabaseUtils.appendEscapedSQLString(s, clause); |
| } |
| } |
| |
| /** |
| * Add the names that are non-null in columns to s, separating |
| * them with commas. |
| */ |
| public static void appendColumns(StringBuilder s, String[] columns) { |
| int n = columns.length; |
| |
| for (int i = 0; i < n; i++) { |
| String column = columns[i]; |
| |
| if (column != null) { |
| if (i > 0) { |
| s.append(", "); |
| } |
| s.append(column); |
| } |
| } |
| s.append(' '); |
| } |
| |
| /** |
| * Perform a query by combining all current settings and the |
| * information passed into this method. |
| * |
| * @param db the database to query on |
| * @param projectionIn A list of which columns to return. Passing |
| * null will return all columns, which is discouraged to prevent |
| * reading data from storage that isn't going to be used. |
| * @param selection A filter declaring which rows to return, |
| * formatted as an SQL WHERE clause (excluding the WHERE |
| * itself). Passing null will return all rows for the given URL. |
| * @param selectionArgs You may include ?s in selection, which |
| * will be replaced by the values from selectionArgs, in order |
| * that they appear in the selection. The values will be bound |
| * as Strings. |
| * @param groupBy A filter declaring how to group rows, formatted |
| * as an SQL GROUP BY clause (excluding the GROUP BY |
| * itself). Passing null will cause the rows to not be grouped. |
| * @param having A filter declare which row groups to include in |
| * the cursor, if row grouping is being used, formatted as an |
| * SQL HAVING clause (excluding the HAVING itself). Passing |
| * null will cause all row groups to be included, and is |
| * required when row grouping is not being used. |
| * @param sortOrder How to order the rows, formatted as an SQL |
| * ORDER BY clause (excluding the ORDER BY itself). Passing null |
| * will use the default sort order, which may be unordered. |
| * @return a cursor over the result set |
| * @see android.content.ContentResolver#query(android.net.Uri, String[], |
| * String, String[], String) |
| */ |
| public Cursor query(SQLiteDatabase db, String[] projectionIn, |
| String selection, String[] selectionArgs, String groupBy, |
| String having, String sortOrder) { |
| return query(db, projectionIn, selection, selectionArgs, groupBy, having, sortOrder, |
| null /* limit */); |
| } |
| |
| /** |
| * Perform a query by combining all current settings and the |
| * information passed into this method. |
| * |
| * @param db the database to query on |
| * @param projectionIn A list of which columns to return. Passing |
| * null will return all columns, which is discouraged to prevent |
| * reading data from storage that isn't going to be used. |
| * @param selection A filter declaring which rows to return, |
| * formatted as an SQL WHERE clause (excluding the WHERE |
| * itself). Passing null will return all rows for the given URL. |
| * @param selectionArgs You may include ?s in selection, which |
| * will be replaced by the values from selectionArgs, in order |
| * that they appear in the selection. The values will be bound |
| * as Strings. |
| * @param groupBy A filter declaring how to group rows, formatted |
| * as an SQL GROUP BY clause (excluding the GROUP BY |
| * itself). Passing null will cause the rows to not be grouped. |
| * @param having A filter declare which row groups to include in |
| * the cursor, if row grouping is being used, formatted as an |
| * SQL HAVING clause (excluding the HAVING itself). Passing |
| * null will cause all row groups to be included, and is |
| * required when row grouping is not being used. |
| * @param sortOrder How to order the rows, formatted as an SQL |
| * ORDER BY clause (excluding the ORDER BY itself). Passing null |
| * will use the default sort order, which may be unordered. |
| * @param limit Limits the number of rows returned by the query, |
| * formatted as LIMIT clause. Passing null denotes no LIMIT clause. |
| * @return a cursor over the result set |
| * @see android.content.ContentResolver#query(android.net.Uri, String[], |
| * String, String[], String) |
| */ |
| public Cursor query(SQLiteDatabase db, String[] projectionIn, |
| String selection, String[] selectionArgs, String groupBy, |
| String having, String sortOrder, String limit) { |
| if (mTables == null) { |
| return null; |
| } |
| |
| String sql = buildQuery( |
| projectionIn, selection, selectionArgs, groupBy, having, |
| sortOrder, limit); |
| |
| if (Log.isLoggable(TAG, Log.DEBUG)) { |
| Log.d(TAG, "Performing query: " + sql); |
| } |
| return db.rawQueryWithFactory( |
| mFactory, sql, selectionArgs, |
| SQLiteDatabase.findEditTable(mTables)); |
| } |
| |
| /** |
| * Construct a SELECT statement suitable for use in a group of |
| * SELECT statements that will be joined through UNION operators |
| * in buildUnionQuery. |
| * |
| * @param projectionIn A list of which columns to return. Passing |
| * null will return all columns, which is discouraged to |
| * prevent reading data from storage that isn't going to be |
| * used. |
| * @param selection A filter declaring which rows to return, |
| * formatted as an SQL WHERE clause (excluding the WHERE |
| * itself). Passing null will return all rows for the given |
| * URL. |
| * @param selectionArgs You may include ?s in selection, which |
| * will be replaced by the values from selectionArgs, in order |
| * that they appear in the selection. The values will be bound |
| * as Strings. |
| * @param groupBy A filter declaring how to group rows, formatted |
| * as an SQL GROUP BY clause (excluding the GROUP BY itself). |
| * Passing null will cause the rows to not be grouped. |
| * @param having A filter declare which row groups to include in |
| * the cursor, if row grouping is being used, formatted as an |
| * SQL HAVING clause (excluding the HAVING itself). Passing |
| * null will cause all row groups to be included, and is |
| * required when row grouping is not being used. |
| * @param sortOrder How to order the rows, formatted as an SQL |
| * ORDER BY clause (excluding the ORDER BY itself). Passing null |
| * will use the default sort order, which may be unordered. |
| * @param limit Limits the number of rows returned by the query, |
| * formatted as LIMIT clause. Passing null denotes no LIMIT clause. |
| * @return the resulting SQL SELECT statement |
| */ |
| public String buildQuery( |
| String[] projectionIn, String selection, String[] selectionArgs, |
| String groupBy, String having, String sortOrder, String limit) { |
| String[] projection = computeProjection(projectionIn); |
| |
| StringBuilder where = new StringBuilder(); |
| |
| if (mWhereClause.length() > 0) { |
| where.append(mWhereClause.toString()); |
| where.append(')'); |
| } |
| |
| // Tack on the user's selection, if present. |
| if (selection != null && selection.length() > 0) { |
| if (mWhereClause.length() > 0) { |
| where.append(" AND "); |
| } |
| |
| where.append('('); |
| where.append(selection); |
| where.append(')'); |
| } |
| |
| return buildQueryString( |
| mDistinct, mTables, projection, where.toString(), |
| groupBy, having, sortOrder, limit); |
| } |
| |
| /** |
| * Construct a SELECT statement suitable for use in a group of |
| * SELECT statements that will be joined through UNION operators |
| * in buildUnionQuery. |
| * |
| * @param typeDiscriminatorColumn the name of the result column |
| * whose cells will contain the name of the table from which |
| * each row was drawn. |
| * @param unionColumns the names of the columns to appear in the |
| * result. This may include columns that do not appear in the |
| * table this SELECT is querying (i.e. mTables), but that do |
| * appear in one of the other tables in the UNION query that we |
| * are constructing. |
| * @param columnsPresentInTable a Set of the names of the columns |
| * that appear in this table (i.e. in the table whose name is |
| * mTables). Since columns in unionColumns include columns that |
| * appear only in other tables, we use this array to distinguish |
| * which ones actually are present. Other columns will have |
| * NULL values for results from this subquery. |
| * @param computedColumnsOffset all columns in unionColumns before |
| * this index are included under the assumption that they're |
| * computed and therefore won't appear in columnsPresentInTable, |
| * e.g. "date * 1000 as normalized_date" |
| * @param typeDiscriminatorValue the value used for the |
| * type-discriminator column in this subquery |
| * @param selection A filter declaring which rows to return, |
| * formatted as an SQL WHERE clause (excluding the WHERE |
| * itself). Passing null will return all rows for the given |
| * URL. |
| * @param selectionArgs You may include ?s in selection, which |
| * will be replaced by the values from selectionArgs, in order |
| * that they appear in the selection. The values will be bound |
| * as Strings. |
| * @param groupBy A filter declaring how to group rows, formatted |
| * as an SQL GROUP BY clause (excluding the GROUP BY itself). |
| * Passing null will cause the rows to not be grouped. |
| * @param having A filter declare which row groups to include in |
| * the cursor, if row grouping is being used, formatted as an |
| * SQL HAVING clause (excluding the HAVING itself). Passing |
| * null will cause all row groups to be included, and is |
| * required when row grouping is not being used. |
| * @return the resulting SQL SELECT statement |
| */ |
| public String buildUnionSubQuery( |
| String typeDiscriminatorColumn, |
| String[] unionColumns, |
| Set<String> columnsPresentInTable, |
| int computedColumnsOffset, |
| String typeDiscriminatorValue, |
| String selection, |
| String[] selectionArgs, |
| String groupBy, |
| String having) { |
| int unionColumnsCount = unionColumns.length; |
| String[] projectionIn = new String[unionColumnsCount]; |
| |
| for (int i = 0; i < unionColumnsCount; i++) { |
| String unionColumn = unionColumns[i]; |
| |
| if (unionColumn.equals(typeDiscriminatorColumn)) { |
| projectionIn[i] = "'" + typeDiscriminatorValue + "' AS " |
| + typeDiscriminatorColumn; |
| } else if (i <= computedColumnsOffset |
| || columnsPresentInTable.contains(unionColumn)) { |
| projectionIn[i] = unionColumn; |
| } else { |
| projectionIn[i] = "NULL AS " + unionColumn; |
| } |
| } |
| return buildQuery( |
| projectionIn, selection, selectionArgs, groupBy, having, |
| null /* sortOrder */, |
| null /* limit */); |
| } |
| |
| /** |
| * Given a set of subqueries, all of which are SELECT statements, |
| * construct a query that returns the union of what those |
| * subqueries return. |
| * @param subQueries an array of SQL SELECT statements, all of |
| * which must have the same columns as the same positions in |
| * their results |
| * @param sortOrder How to order the rows, formatted as an SQL |
| * ORDER BY clause (excluding the ORDER BY itself). Passing |
| * null will use the default sort order, which may be unordered. |
| * @param limit The limit clause, which applies to the entire union result set |
| * |
| * @return the resulting SQL SELECT statement |
| */ |
| public String buildUnionQuery(String[] subQueries, String sortOrder, String limit) { |
| StringBuilder query = new StringBuilder(128); |
| int subQueryCount = subQueries.length; |
| String unionOperator = mDistinct ? " UNION " : " UNION ALL "; |
| |
| for (int i = 0; i < subQueryCount; i++) { |
| if (i > 0) { |
| query.append(unionOperator); |
| } |
| query.append(subQueries[i]); |
| } |
| appendClause(query, " ORDER BY ", sortOrder); |
| appendClause(query, " LIMIT ", limit); |
| return query.toString(); |
| } |
| |
| private String[] computeProjection(String[] projectionIn) { |
| if (projectionIn != null && projectionIn.length > 0) { |
| if (mProjectionMap != null) { |
| String[] projection = new String[projectionIn.length]; |
| int length = projectionIn.length; |
| |
| for (int i = 0; i < length; i++) { |
| String userColumn = projectionIn[i]; |
| String column = mProjectionMap.get(userColumn); |
| |
| if (column != null) { |
| projection[i] = column; |
| continue; |
| } |
| |
| if (userColumn.contains(" AS ") |
| || userColumn.contains(" as ")) { |
| /* A column alias already exist */ |
| projection[i] = userColumn; |
| continue; |
| } |
| |
| throw new IllegalArgumentException("Invalid column " |
| + projectionIn[i]); |
| } |
| return projection; |
| } else { |
| return projectionIn; |
| } |
| } else if (mProjectionMap != null) { |
| // Return all columns in projection map. |
| Set<Entry<String, String>> entrySet = mProjectionMap.entrySet(); |
| String[] projection = new String[entrySet.size()]; |
| Iterator<Entry<String, String>> entryIter = entrySet.iterator(); |
| int i = 0; |
| |
| while (entryIter.hasNext()) { |
| Entry<String, String> entry = entryIter.next(); |
| |
| // Don't include the _count column when people ask for no projection. |
| if (entry.getKey().equals(BaseColumns._COUNT)) { |
| continue; |
| } |
| projection[i++] = entry.getValue(); |
| } |
| return projection; |
| } |
| return null; |
| } |
| } |