/** Deduces the names and types of a table's columns by reading the first line of a CSV file. */
static RelDataType deduceRowType(
JavaTypeFactory typeFactory, File file, List<CsvFieldType> fieldTypes) {
final List<RelDataType> types = new ArrayList<RelDataType>();
final List<String> names = new ArrayList<String>();
CSVReader reader = null;
try {
reader = openCsv(file);
final String[] strings = reader.readNext();
for (String string : strings) {
final String name;
final CsvFieldType fieldType;
final int colon = string.indexOf(':');
if (colon >= 0) {
name = string.substring(0, colon);
String typeString = string.substring(colon + 1);
fieldType = CsvFieldType.of(typeString);
if (fieldType == null) {
System.out.println(
"WARNING: Found unknown type: "
+ typeString
+ " in file: "
+ file.getAbsolutePath()
+ " for column: "
+ name
+ ". Will assume the type of column is string");
}
} else {
name = string;
fieldType = null;
}
final RelDataType type;
if (fieldType == null) {
type = typeFactory.createJavaType(String.class);
} else {
type = fieldType.toType(typeFactory);
}
names.add(name);
types.add(type);
if (fieldTypes != null) {
fieldTypes.add(fieldType);
}
}
} catch (IOException e) {
// ignore
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
// ignore
}
}
}
if (names.isEmpty()) {
names.add("line");
types.add(typeFactory.createJavaType(String.class));
}
return typeFactory.createStructType(Pair.zip(names, types));
}
@Override
public String visitLiteral(RexLiteral rexLiteral) {
Object v = rexLiteral.getValue();
RelDataType ty = rexLiteral.getType();
switch (rexLiteral.getTypeName()) {
case BOOLEAN:
return v.toString();
case CHAR:
return CompilerUtil.escapeJavaString(((NlsString) v).getValue(), true);
case NULL:
return "((" + ((Class<?>) typeFactory.getJavaClass(ty)).getCanonicalName() + ")null)";
case DOUBLE:
case BIGINT:
case DECIMAL:
switch (ty.getSqlTypeName()) {
case TINYINT:
case SMALLINT:
case INTEGER:
return Long.toString(((BigDecimal) v).longValueExact());
case BIGINT:
return Long.toString(((BigDecimal) v).longValueExact()) + 'L';
case DECIMAL:
case FLOAT:
case REAL:
case DOUBLE:
return Util.toScientificNotation((BigDecimal) v);
}
break;
default:
throw new UnsupportedOperationException();
}
return null;
}
// Only generate inline expressions when comparing primitive types
private boolean primitiveCompareExpr(SqlOperator op, RelDataType type) {
final Primitive primitive = Primitive.ofBoxOr(typeFactory.getJavaClass(type));
return primitive != null
&& (op == LESS_THAN
|| op == LESS_THAN_OR_EQUAL
|| op == GREATER_THAN
|| op == GREATER_THAN_OR_EQUAL);
}
private String javaTypeName(RexNode node) {
Type ty = typeFactory.getJavaClass(node.getType());
return ((Class<?>) ty).getCanonicalName();
}
