clause.Eq{Column: column, Value: (*string)(nil)},
			clause.Eq{Column: column, Value: (*int)(nil)},
			clause.Eq{Column: column, Value: (*bool)(nil)},
			clause.Eq{Column: column, Value: (interface{})(nil)},
			clause.Eq{Column: column, Value: sql.NullString{String: "", Valid: false}},
		},
		Result: "`column-name` IS NULL",
	}, {
		Expressions: []clause.Expression{

					}
				} else {
					tx.Clauses(clause.Eq{Column: ref.ForeignKey.DBName, Value: ref.PrimaryValue})
				}
			}

			_, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, primaryFields)
			if column, values := schema.ToQueryValues(rel.JoinTable.Table, joinPrimaryKeys, pvs); len(values) > 0 {
				tx.Where(clause.IN{Column: column, Values: values})
			} else {
				return ErrPrimaryKeyRequired

			}},
			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?",
			[]interface{}{"1", "jinzhu", 18},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{

					clauseSelect.Columns[idx] = clause.Column{Name: name, Raw: true}
				} else if f := db.Statement.Schema.LookUpField(name); f != nil {
					clauseSelect.Columns[idx] = clause.Column{Name: f.DBName}
				} else {
					clauseSelect.Columns[idx] = clause.Column{Name: name, Raw: true}
				}
			}
		} else if db.Statement.Schema != nil && len(db.Statement.Omits) > 0 {

				matchedFieldCount := make(map[string]int, len(columns))
				for idx, column := range columns {
					if field := sch.LookUpField(column); field != nil && field.Readable {
						fields[idx] = field
						if count, ok := matchedFieldCount[column]; ok {
							// handle duplicate fields
							for _, selectField := range sch.Fields {
								if selectField.DBName == column && selectField.Readable {
									if count == 0 {

			if stmt.Schema != nil && len(values.Columns) >= 1 {
				selectColumns, restricted := stmt.SelectAndOmitColumns(true, true)

				columns := make([]string, 0, len(values.Columns)-1)
				for _, column := range values.Columns {
					if field := stmt.Schema.LookUpField(column.Name); field != nil {
						if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {

				}
			} else {
				results[col] = result
			}
		} else {
			results[column] = result
		}
	}

	// select columns
	for _, column := range stmt.Selects {
		processColumn(column, true)
	}

	// omit columns
	for _, column := range stmt.Omits {
		processColumn(column, false)
	}

	if stmt.Schema != nil {
		for _, field := range stmt.Schema.FieldsByName {

					}

					if len(selectExpr.Exprs) == 0 {
						selectExpr.Exprs = []clause.Expression{clause.Expr{SQL: "*", Vars: []interface{}{}}}
					}

					partitionBy := clause.CommaExpression{}
					for _, column := range refColumns {
						partitionBy.Exprs = append(partitionBy.Exprs, clause.Expr{SQL: "?", Vars: []interface{}{clause.Column{Name: column.Name}}})
					}

				"name": "my name",
			},
			expect: clause.Values{
				Columns: []clause.Column{{Name: "name"}},
				Values:  [][]interface{}{{"my name"}},
			},
		},
		{
			name: "Test convert int value",
			input: map[string]interface{}{
				"age": 18,
			},
			expect: clause.Values{
				Columns: []clause.Column{{Name: "age"}},
				Values:  [][]interface{}{{18}},
			},
		},
		{

func (ns NamingStrategy) CheckerName(table, column string) string {
	return ns.formatName("chk", table, column)
}

// IndexName generate index name
func (ns NamingStrategy) IndexName(table, column string) string {
	return ns.formatName("idx", table, ns.toDBName(column))
}

// UniqueName generate unique constraint name
func (ns NamingStrategy) UniqueName(table, column string) string {