Method Count

finisher_api.go:454–514

(count *int64)

}

func (db *DB) Count(count *int64) (tx *DB) {
	tx = db.getInstance()
	if tx.Statement.Model == nil {
		tx.Statement.Model = tx.Statement.Dest
		defer func() {
			tx.Statement.Model = nil
		}()
	}

	if selectClause, ok := db.Statement.Clauses["SELECT"]; ok {
		defer func() {
			tx.Statement.Clauses["SELECT"] = selectClause
		}()
	} else {
		defer delete(tx.Statement.Clauses, "SELECT")
	}

	if len(tx.Statement.Selects) == 0 {
		tx.Statement.AddClause(clause.Select{Expression: clause.Expr{SQL: "count(*)"}})
	} else if !strings.HasPrefix(strings.TrimSpace(strings.ToLower(tx.Statement.Selects[0])), "count(") {
		expr := clause.Expr{SQL: "count(*)"}

		if len(tx.Statement.Selects) == 1 {
			dbName := tx.Statement.Selects[0]
			fields := strings.FieldsFunc(dbName, utils.IsInvalidDBNameChar)
			if len(fields) == 1 || (len(fields) == 3 && (strings.ToUpper(fields[1]) == "AS" || fields[1] == ".")) {
				if tx.Statement.Parse(tx.Statement.Model) == nil {
					if f := tx.Statement.Schema.LookUpField(dbName); f != nil {
						dbName = f.DBName
					}
				}

				if tx.Statement.Distinct {
					expr = clause.Expr{SQL: "COUNT(DISTINCT(?))", Vars: []interface{}{clause.Column{Name: dbName}}}
				} else if dbName != "*" {
					expr = clause.Expr{SQL: "COUNT(?)", Vars: []interface{}{clause.Column{Name: dbName}}}
				}
			}
		}

		tx.Statement.AddClause(clause.Select{Expression: expr})
	}

	if orderByClause, ok := db.Statement.Clauses["ORDER BY"]; ok {
		if _, ok := db.Statement.Clauses["GROUP BY"]; !ok {
			delete(tx.Statement.Clauses, "ORDER BY")
			defer func() {
				tx.Statement.Clauses["ORDER BY"] = orderByClause
			}()
		}
	}

	tx.Statement.Dest = count
	tx = tx.callbacks.Query().Execute(tx)

	if _, ok := db.Statement.Clauses["GROUP BY"]; ok || tx.RowsAffected != 1 {
		*count = tx.RowsAffected
	}