
de.greenrobot.dao.internal.SqlUtils Maven / Gradle / Ivy
/*
* Copyright (C) 2011-2015 Markus Junginger, greenrobot (http://greenrobot.de)
*
* 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 de.greenrobot.dao.internal;
import de.greenrobot.dao.DaoException;
import de.greenrobot.dao.Property;
/** Helper class to create SQL statements as used by greenDAO internally. */
public class SqlUtils {
private final static char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();
public static StringBuilder appendProperty(StringBuilder builder, String tablePrefix, Property property) {
if (tablePrefix != null) {
builder.append(tablePrefix).append('.');
}
builder.append('"').append(property.columnName).append('"');
return builder;
}
public static StringBuilder appendColumn(StringBuilder builder, String column) {
builder.append('"').append(column).append('"');
return builder;
}
public static StringBuilder appendColumn(StringBuilder builder, String tableAlias, String column) {
builder.append(tableAlias).append(".\"").append(column).append('"');
return builder;
}
public static StringBuilder appendColumns(StringBuilder builder, String tableAlias, String[] columns) {
int length = columns.length;
for (int i = 0; i < length; i++) {
appendColumn(builder, tableAlias, columns[i]);
if (i < length - 1) {
builder.append(',');
}
}
return builder;
}
public static StringBuilder appendColumns(StringBuilder builder, String[] columns) {
int length = columns.length;
for (int i = 0; i < length; i++) {
builder.append('"').append(columns[i]).append('"');
if (i < length - 1) {
builder.append(',');
}
}
return builder;
}
public static StringBuilder appendPlaceholders(StringBuilder builder, int count) {
for (int i = 0; i < count; i++) {
if (i < count - 1) {
builder.append("?,");
} else {
builder.append('?');
}
}
return builder;
}
public static StringBuilder appendColumnsEqualPlaceholders(StringBuilder builder, String[] columns) {
for (int i = 0; i < columns.length; i++) {
appendColumn(builder, columns[i]).append("=?");
if (i < columns.length - 1) {
builder.append(',');
}
}
return builder;
}
public static StringBuilder appendColumnsEqValue(StringBuilder builder, String tableAlias, String[] columns) {
for (int i = 0; i < columns.length; i++) {
appendColumn(builder, tableAlias, columns[i]).append("=?");
if (i < columns.length - 1) {
builder.append(',');
}
}
return builder;
}
public static String createSqlInsert(String insertInto, String tablename, String[] columns) {
StringBuilder builder = new StringBuilder(insertInto);
builder.append('"').append(tablename).append('"').append(" (");
appendColumns(builder, columns);
builder.append(") VALUES (");
appendPlaceholders(builder, columns.length);
builder.append(')');
return builder.toString();
}
/** Creates an select for given columns with a trailing space */
public static String createSqlSelect(String tablename, String tableAlias, String[] columns, boolean distinct) {
if (tableAlias == null || tableAlias.length() < 0) {
throw new DaoException("Table alias required");
}
StringBuilder builder = new StringBuilder(distinct ? "SELECT DISTINCT " : "SELECT ");
SqlUtils.appendColumns(builder, tableAlias, columns).append(" FROM ");
builder.append('"').append(tablename).append('"').append(' ').append(tableAlias).append(' ');
return builder.toString();
}
/** Creates SELECT COUNT(*) with a trailing space. */
public static String createSqlSelectCountStar(String tablename, String tableAliasOrNull) {
StringBuilder builder = new StringBuilder("SELECT COUNT(*) FROM ");
builder.append('"').append(tablename).append('"').append(' ');
if (tableAliasOrNull != null) {
builder.append(tableAliasOrNull).append(' ');
}
return builder.toString();
}
/** Remember: SQLite does not support joins nor table alias for DELETE. */
public static String createSqlDelete(String tablename, String[] columns) {
String quotedTablename = '"' + tablename + '"';
StringBuilder builder = new StringBuilder("DELETE FROM ");
builder.append(quotedTablename);
if (columns != null && columns.length > 0) {
builder.append(" WHERE ");
appendColumnsEqValue(builder, quotedTablename, columns);
}
return builder.toString();
}
public static String createSqlUpdate(String tablename, String[] updateColumns, String[] whereColumns) {
String quotedTablename = '"' + tablename + '"';
StringBuilder builder = new StringBuilder("UPDATE ");
builder.append(quotedTablename).append(" SET ");
appendColumnsEqualPlaceholders(builder, updateColumns);
builder.append(" WHERE ");
appendColumnsEqValue(builder, quotedTablename, whereColumns);
return builder.toString();
}
public static String createSqlCount(String tablename) {
return "SELECT COUNT(*) FROM \"" + tablename +'"';
}
public static String escapeBlobArgument(byte[] bytes) {
return "X'" + toHex(bytes) + '\'';
}
public static String toHex(byte[] bytes) {
char[] hexChars = new char[bytes.length * 2];
for (int i = 0; i < bytes.length; i++) {
int byteValue = bytes[i] & 0xFF;
hexChars[i * 2] = HEX_ARRAY[byteValue >>> 4];
hexChars[i * 2 + 1] = HEX_ARRAY[byteValue & 0x0F];
}
return new String(hexChars);
}
}
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