baize/framework/core/infrastructure/database/clause/select.go

package clause

import "strings"

type Select struct {
	selectClauses []string
	fromClause    *From
	otherClauses  []Clause
}

func NewSelect(selectClauses []string, fromClause *From, otherClauses ...Clause) *Select {
	return &Select{
		selectClauses: selectClauses,
		fromClause:    fromClause,
		otherClauses:  otherClauses,
	}
}

func (clause *Select) Clause() (string, error) {
	selectClauseBuilder := strings.Builder{}
	if clause.selectClauses == nil || len(clause.selectClauses) == 0 {
		selectClauseBuilder.WriteString("*\n")
	} else {
		for i, selectClause := range clause.selectClauses {
			selectClauseBuilder.WriteString("  " + selectClause)

			if i < len(clause.selectClauses)-1 {
				selectClauseBuilder.WriteString(",\n")
			} else {
				selectClauseBuilder.WriteString("\n")
			}
		}
	}

	fromClause, err := clause.fromClause.Clause()
	if err != nil {
		return "", err
	}

	otherClauseBuilder := strings.Builder{}
	for _, otherClause := range clause.otherClauses {
		otherClauseStr, err := otherClause.Clause()
		if err != nil {
			return "", err
		}

		otherClauseBuilder.WriteString(otherClauseStr)
	}

	clauseBuilder := strings.Builder{}
	clauseBuilder.WriteString("SELECT\n")
	clauseBuilder.WriteString(selectClauseBuilder.String())
	clauseBuilder.WriteString(fromClause)
	clauseBuilder.WriteString(otherClauseBuilder.String())

	return clauseBuilder.String(), nil
}

func (clause *Select) Args() []any {
	args := make([]any, 0)

	args = append(args, clause.fromClause.Args()...)

	for _, otherClause := range clause.otherClauses {
		args = append(args, otherClause.Args()...)
	}

	return args
}