Method castTo

fe/src/main/java/org/apache/impala/analysis/Expr.java:1612–1626

Casts this expr to a specific target type. It checks the validity of the cast according to 'compatibility' and calls uncheckedCastTo(). @param targetType type to be cast to @param compatibility compatibility level that defines the relation between 'targetType' and the type

(Type targetType, TypeCompatibility compatibility)

   *           failure to convert a string literal to a date literal
   */
  public final Expr castTo(Type targetType, TypeCompatibility compatibility)
      throws AnalysisException {
    Type type = Type.getAssignmentCompatibleType(this.type_, targetType, compatibility);
    Preconditions.checkState(type.isValid(), "cast %s to %s", this.type_, targetType);
    // If the targetType is NULL_TYPE then ignore the cast because NULL_TYPE
    // is compatible with all types and no cast is necessary.
    if (targetType.isNull()) return this;
    // If decimal, cast to the target type.
    if (targetType.isDecimal()) return uncheckedCastTo(targetType, compatibility);
    // If they match, cast to the type both values can be assigned to (the definition of
    // getAssignmentCompatibleType), which implies no loss of precision. Note that
    // getAssignmentCompatibleType always returns a "real" (not wildcard) type.
    if (type.matchesType(targetType)) return uncheckedCastTo(type, compatibility);
    throw new SqlCastException("targetType=" + targetType + " type=" + type);
  }

  public final Expr castTo(Type targetType) throws AnalysisException {
    return castTo(targetType, TypeCompatibility.DEFAULT);