/**
* Returns the result of replacing each column reference c in the inverse expression with : - the
* quoted and escaped data value of column c in r, if c is a referenced column in the term map -
* the column name of column c, otherwise
*
* @param stringTemplate
* @param dbValues
* @param columnReferences
* @param dbTypes
* @return
* @throws R2RMLDataError
* @throws SQLException
* @throws UnsupportedEncodingException
* @throws MalformedURLException
*/
public static String extractColumnValueFromInverseExpression(
String inverseExpression,
Map<ColumnIdentifier, byte[]> dbValues,
Set<ColumnIdentifier> columnReferences)
throws R2RMLDataError, SQLException, UnsupportedEncodingException {
// Let result be the template string
String result = inverseExpression;
if (dbValues == null) return null;
for (ColumnIdentifier column : dbValues.keySet()) {
// A quoted and escaped data value is any SQL
// string that matches the <literal> or <null specification>
// productions of [SQL2].
// This string can be used in a SQL query to specify a SQL data
// value.
String value = null;
if (dbValues.get(column) == null) value = "NULL";
else {
// Extract db value
byte[] byteValue = dbValues.get(column);
// Apply cast to string to the SQL data value
value = new String(byteValue, "UTF-8");
}
result = column.replaceAll(result, "'" + value + "'");
// Test backslashes result =
/*
* result.replaceAll("\\{\\\"" + column + "\\\"\\}", "'" + result +
* "'"); result = result.replaceAll("\\{\\'" + column + "\\'\\}",
* "'" + result + "'"); result = result.replaceAll("\\{\\`" + column
* + "\\`\\}", "'" + result + "'");
*/
}
// Replace curly braces of not referenced column references
for (ColumnIdentifier column : columnReferences) {
if (!dbValues.keySet().contains(column)) {
result = column.replaceAll(result, column.toString());
// result = result.replaceAll("\\{\\'" + columnStr + "\\'\\}", columnStr);
// result = result.replaceAll("\\{\\`" + columnStr + "\\`\\}", columnStr);
}
}
// Curly braces that do not enclose column names MUST be
// escaped by a backslash character (“\”).
result = result.replaceAll("\\\\\\{", "{");
result = result.replaceAll("\\\\\\}", "}");
return result;
}
