package net.sourceforge.squirrel_sql.client.session;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class EditableSqlCheck
{
private static final int ALLOWS_EDITING_FALSE = 0;
private static final int ALLOWS_EDITING_TRUE = 1;
private static final int ALLOWS_EDITING_UNKNOWN = 2;
private String _tableNameFromSQL = null;
public EditableSqlCheck(SQLExecutionInfo exInfo)
{
if(null == exInfo || null == exInfo.getSQL())
{
return;
}
_tableNameFromSQL = getTableFromSQLIntern(exInfo.getSQL());
}
private String getTableFromSQLIntern(String sql)
{
Pattern patternBeforeTable = Pattern.compile("SELECT\\s+[A-Z0-9_\\*\\.',\\s]*\\s+FROM\\s+([A-Z0-9_\\.]+)");
sql = sql.toUpperCase().trim();
// Bug 1371587 - remove useless accent characters if they exist
sql = sql.replaceAll("\\`", "");
Matcher matcher;
matcher = patternBeforeTable.matcher(sql);
if(false == matcher.find())
{
return null;
}
String table = matcher.group(1);
String behindTable = sql.substring(matcher.end(1)).trim();
int ret = behindTableAllowsEditing(behindTable);
if(ALLOWS_EDITING_UNKNOWN == ret)
{
// This might be because an table alias is used maybe with an AS before it.
Pattern patternBehindTable;
if(behindTable.startsWith("AS") && 2 < behindTable.length() && Character.isWhitespace(behindTable.charAt(2)))
{
patternBehindTable = Pattern.compile("AS\\s+([A-Z0-9_]+)\\s+");
}
else
{
patternBehindTable = Pattern.compile("([A-Z0-9_]+)\\s+|[A-Z0-9_]+$");
}
matcher = patternBehindTable.matcher(behindTable);
if(false == matcher.find())
{
return null;
}
String alias = matcher.group(0);
String behindAlias = behindTable.substring(matcher.end(0)).trim();
ret = behindTableAllowsEditing(behindAlias);
if(ALLOWS_EDITING_TRUE == ret)
{
return table;
}
else
{
return null;
}
}
else if(ALLOWS_EDITING_TRUE == ret)
{
return table;
}
else //(ALLOWS_EDITING_FALSE == ret)
{
return null;
}
}
private int behindTableAllowsEditing(String behindTable)
{
if(0 == behindTable.length())
{
return ALLOWS_EDITING_TRUE;
}
else if( behindTable.startsWith("WHERE")
|| behindTable.startsWith("ORDER")
|| behindTable.startsWith("GROUP"))
{
return ALLOWS_EDITING_TRUE;
}
else if( behindTable.startsWith(",")
|| behindTable.startsWith("INNER")
|| behindTable.startsWith("LEFT")
|| behindTable.startsWith("RIGHT")
|| behindTable.startsWith("OUTER")
|| behindTable.startsWith(","))
{
return ALLOWS_EDITING_FALSE;
}
else
{
return ALLOWS_EDITING_UNKNOWN;
}
}
public boolean allowsEditing()
{
return null != _tableNameFromSQL;
}
public String getTableNameFromSQL()
{
return _tableNameFromSQL;
}
}