Replaced more panic calls with returned error

Author: Mark Songhurst

column.go

@@ -90,17 +90,17 @@ func NewColumn(h api.SQLHSTMT, idx int) (Column, error) {
 		var v api.SQLGUID
 		return NewBindableColumn(b, api.SQL_C_GUID, int(unsafe.Sizeof(v))), nil
 	case api.SQL_CHAR, api.SQL_VARCHAR:
-		return NewVariableWidthColumn(b, api.SQL_C_CHAR, size), nil
+		return NewVariableWidthColumn(b, api.SQL_C_CHAR, size)
 	case api.SQL_WCHAR, api.SQL_WVARCHAR:
-		return NewVariableWidthColumn(b, api.SQL_C_WCHAR, size), nil
+		return NewVariableWidthColumn(b, api.SQL_C_WCHAR, size)
 	case api.SQL_BINARY, api.SQL_VARBINARY:
-		return NewVariableWidthColumn(b, api.SQL_C_BINARY, size), nil
+		return NewVariableWidthColumn(b, api.SQL_C_BINARY, size)
 	case api.SQL_LONGVARCHAR:
-		return NewVariableWidthColumn(b, api.SQL_C_CHAR, 0), nil
+		return NewVariableWidthColumn(b, api.SQL_C_CHAR, 0)
 	case api.SQL_WLONGVARCHAR, api.SQL_SS_XML:
-		return NewVariableWidthColumn(b, api.SQL_C_WCHAR, 0), nil
+		return NewVariableWidthColumn(b, api.SQL_C_WCHAR, 0)
 	case api.SQL_LONGVARBINARY:
-		return NewVariableWidthColumn(b, api.SQL_C_BINARY, 0), nil
+		return NewVariableWidthColumn(b, api.SQL_C_BINARY, 0)
 	default:
 		return nil, fmt.Errorf("unsupported column type %d", sqltype)
 	}
@@ -199,10 +199,10 @@ func NewBindableColumn(b *BaseColumn, ctype api.SQLSMALLINT, bufSize int) *Binda
 	return c
 }
 
-func NewVariableWidthColumn(b *BaseColumn, ctype api.SQLSMALLINT, colWidth api.SQLULEN) Column {
+func NewVariableWidthColumn(b *BaseColumn, ctype api.SQLSMALLINT, colWidth api.SQLULEN) (Column, error) {
 	if colWidth == 0 || colWidth > 1024 {
 		b.CType = ctype
-		return &NonBindableColumn{b}
+		return &NonBindableColumn{b}, nil
 	}
 	l := int(colWidth)
 	switch ctype {
@@ -214,11 +214,11 @@ func NewVariableWidthColumn(b *BaseColumn, ctype api.SQLSMALLINT, colWidth api.S
 	case api.SQL_C_BINARY:
 		// nothing to do
 	default:
-		panic(fmt.Errorf("do not know how wide column of ctype %d is", ctype))
+		return nil, fmt.Errorf("do not know how wide column of ctype %d is", ctype)
 	}
 	c := NewBindableColumn(b, ctype, l)
 	c.IsVariableWidth = true
-	return c
+	return c, nil
 }
 
 func (c *BindableColumn) Bind(h api.SQLHSTMT, idx int) (bool, error) {
@@ -242,7 +242,7 @@ func (c *BindableColumn) Value(h api.SQLHSTMT, idx int) (driver.Value, error) {
 		return nil, nil
 	}
 	if !c.IsVariableWidth && int(c.Len) != c.Size {
-		panic(fmt.Errorf("wrong column #%d length %d returned, %d expected", idx, c.Len, c.Size))
+		return nil, fmt.Errorf("wrong column #%d length %d returned, %d expected", idx, c.Len, c.Size)
 	}
 	return c.BaseColumn.Value(c.Buffer[:c.Len])
 }

error.go

@@ -58,7 +58,7 @@ func NewError(apiName string, handle interface{}) error {
 			break
 		}
 		if IsError(ret) {
-			panic(fmt.Errorf("SQLGetDiagRec failed: ret=%d", ret))
+			return fmt.Errorf("SQLGetDiagRec failed: ret=%d", ret)
 		}
 		r := DiagRecord{
 			State:       api.UTF16ToString(state),