How to use

convertTypeToSpec

method

in

org.apache.calcite.sql.type.SqlTypeUtil

private SqlNode maybeCast(SqlNode node, RelDataType currentType,
  RelDataType desiredType) {
  return currentType.equals(desiredType)
    || (currentType.isNullable() != desiredType.isNullable()
        && typeFactory.createTypeWithNullability(currentType,
    desiredType.isNullable()).equals(desiredType))
    ? node
    : SqlStdOperatorTable.CAST.createCall(SqlParserPos.ZERO,
    node, SqlTypeUtil.convertTypeToSpec(desiredType));
}

 private SqlNode getCastedSqlNode(SqlNode argInput, RelDataType varType,
   SqlParserPos pos, RexNode argRex) {
  SqlNode arg;
  if (argRex != null && !argRex.getType().equals(varType)) {
   arg = SqlStdOperatorTable.CAST.createCall(
     pos, argInput, SqlTypeUtil.convertTypeToSpec(varType));
  } else {
   arg = argInput;
  }
  return arg;
 }
}

 private SqlNode getCastedSqlNode(SqlNode argInput, RelDataType varType,
   SqlParserPos pos, RexNode argRex) {
  SqlNode arg;
  if (argRex != null && !argRex.getType().equals(varType)) {
   arg = SqlStdOperatorTable.CAST.createCall(
     pos, argInput, SqlTypeUtil.convertTypeToSpec(varType));
  } else {
   arg = argInput;
  }
  return arg;
 }
}

 private SqlNode getCastedSqlNode(SqlNode argInput, RelDataType varType,
   SqlParserPos pos, RexNode argRex) {
  SqlNode arg;
  if (argRex != null && !argRex.getType().equals(varType)) {
   arg = SqlStdOperatorTable.CAST.createCall(
     pos, argInput, SqlTypeUtil.convertTypeToSpec(varType));
  } else {
   arg = argInput;
  }
  return arg;
 }
}

 private SqlNode getCastedSqlNode(SqlNode argInput, RelDataType varType,
   SqlParserPos pos, RexNode argRex) {
  SqlNode arg;
  if (argRex != null && !argRex.getType().equals(varType)) {
   arg = SqlStdOperatorTable.CAST.createCall(
     pos, argInput, SqlTypeUtil.convertTypeToSpec(varType));
  } else {
   arg = argInput;
  }
  return arg;
 }
}

/**
 * Creates and registers a convertlet for an operator in which
 * the SQL representation needs the result type appended
 * as an extra argument (e.g. CAST).
 *
 * @param op operator instance
 */
private void registerTypeAppendOp(final SqlOperator op) {
 registerOp(
   op, (converter, call) -> {
    SqlNode[] operands =
      convertExpressionList(converter, call.operands);
    if (operands == null) {
     return null;
    }
    List<SqlNode> operandList =
      new ArrayList<>(Arrays.asList(operands));
    SqlDataTypeSpec typeSpec =
      SqlTypeUtil.convertTypeToSpec(call.getType());
    operandList.add(typeSpec);
    return new SqlBasicCall(
      op,
      operandList.toArray(new SqlNode[0]),
      SqlParserPos.ZERO);
   });
}

private SqlNode maybeCast(SqlNode node, RelDataType currentType,
  RelDataType desiredType) {
 return currentType.equals(desiredType)
   || (currentType.isNullable() != desiredType.isNullable()
     && typeFactory.createTypeWithNullability(currentType,
       desiredType.isNullable()).equals(desiredType))
   ? node
   : SqlStdOperatorTable.CAST.createCall(SqlParserPos.ZERO,
     node, SqlTypeUtil.convertTypeToSpec(desiredType));
}

private SqlNode maybeCast(SqlNode node, RelDataType currentType,
  RelDataType desiredType) {
 return currentType.equals(desiredType)
   || (currentType.isNullable() != desiredType.isNullable()
     && typeFactory.createTypeWithNullability(currentType,
       desiredType.isNullable()).equals(desiredType))
   ? node
   : SqlStdOperatorTable.CAST.createCall(SqlParserPos.ZERO,
     node, SqlTypeUtil.convertTypeToSpec(desiredType));
}

/**
 * Creates and registers a convertlet for an operator in which
 * the SQL representation needs the result type appended
 * as an extra argument (e.g. CAST).
 *
 * @param op operator instance
 */
private void registerTypeAppendOp(final SqlOperator op) {
 registerOp(
   op, (converter, call) -> {
    SqlNode[] operands =
      convertExpressionList(converter, call.operands);
    if (operands == null) {
     return null;
    }
    List<SqlNode> operandList =
      new ArrayList<>(Arrays.asList(operands));
    SqlDataTypeSpec typeSpec =
      SqlTypeUtil.convertTypeToSpec(call.getType());
    operandList.add(typeSpec);
    return new SqlBasicCall(
      op,
      operandList.toArray(new SqlNode[0]),
      SqlParserPos.ZERO);
   });
}

public SqlNode getCastSpec(RelDataType type) {
 if (type instanceof BasicSqlType) {
  return new SqlDataTypeSpec(
    new SqlIdentifier(type.getSqlTypeName().name(), SqlParserPos.ZERO),
      type.getPrecision(),
      type.getScale(),
      type.getCharset() != null
        && supportsCharSet()
        ? type.getCharset().name()
        : null,
      null,
      SqlParserPos.ZERO);
 }
 return SqlTypeUtil.convertTypeToSpec(type);
}

@Before
public void setUp() {
 JavaTypeFactory typeFactory = new JavaTypeFactoryImpl(RelDataTypeSystem.DEFAULT);
 integerDataType = typeFactory.createSqlType(SqlTypeName.INTEGER);
 integerType = SqlTypeUtil.convertTypeToSpec(integerDataType);
 rexBuilder = new RexBuilder(typeFactory);
}

@Before
public void setUp() {
 JavaTypeFactory typeFactory = new JavaTypeFactoryImpl(RelDataTypeSystem.DEFAULT);
 integerDataType = typeFactory.createSqlType(SqlTypeName.INTEGER);
 integerType = SqlTypeUtil.convertTypeToSpec(integerDataType);
 rexBuilder = new RexBuilder(typeFactory);
}

public SqlNode getCastSpec(RelDataType type) {
 if (type instanceof BasicSqlType) {
  int precision = type.getPrecision();
  switch (type.getSqlTypeName()) {
  case VARCHAR:
   // if needed, adjust varchar length to max length supported by the system
   int maxPrecision = getTypeSystem().getMaxPrecision(type.getSqlTypeName());
   if (type.getPrecision() > maxPrecision) {
    precision = maxPrecision;
   }
  }
  return new SqlDataTypeSpec(
    new SqlIdentifier(type.getSqlTypeName().name(), SqlParserPos.ZERO),
      precision,
      type.getScale(),
      type.getCharset() != null
        && supportsCharSet()
        ? type.getCharset().name()
        : null,
      null,
      SqlParserPos.ZERO);
 }
 return SqlTypeUtil.convertTypeToSpec(type);
}

private SqlNode toSql(RelDataType type) {
 switch (dialect.getDatabaseProduct()) {
  case MYSQL:
   switch (type.getSqlTypeName()) {
    case VARCHAR:
     // MySQL doesn't have a VARCHAR type, only CHAR.
     return new SqlDataTypeSpec(new SqlIdentifier("CHAR", POS),
       type.getPrecision(), -1, null, null, POS);
    case INTEGER:
     return new SqlDataTypeSpec(new SqlIdentifier("_UNSIGNED", POS),
       type.getPrecision(), -1, null, null, POS);
   }
   break;
 }
 if (type instanceof BasicSqlType) {
  return new SqlDataTypeSpec(
    new SqlIdentifier(type.getSqlTypeName().name(), POS),
    type.getPrecision(),
    type.getScale(),
    type.getCharset() != null
      && dialect.supportsCharSet()
      ? type.getCharset().name()
      : null,
    null,
    POS);
 }
 return SqlTypeUtil.convertTypeToSpec(type);
 //throw new AssertionError(type); // TODO: implement
}