package psql import ( "bytes" "errors" "fmt" "io" "github.com/dosco/super-graph/jsn" "github.com/dosco/super-graph/qcode" ) func (co *Compiler) compileMutation(qc *qcode.QCode, w *bytes.Buffer, vars Variables) (uint32, error) { if len(qc.Selects) == 0 { return 0, errors.New("empty query") } c := &compilerContext{w, qc.Selects, co} root := &qc.Selects[0] switch root.Action { case qcode.ActionInsert: if _, err := c.renderInsert(qc, w, vars); err != nil { return 0, err } case qcode.ActionUpdate: if _, err := c.renderUpdate(qc, w, vars); err != nil { return 0, err } case qcode.ActionDelete: if _, err := c.renderDelete(qc, w, vars); err != nil { return 0, err } default: return 0, errors.New("valid mutations are 'insert' and 'update'") } return c.compileQuery(qc, w) } func (c *compilerContext) renderInsert(qc *qcode.QCode, w *bytes.Buffer, vars Variables) (uint32, error) { root := &qc.Selects[0] insert, ok := vars[root.ActionVar] if !ok { return 0, fmt.Errorf("Variable '%s' not defined", root.ActionVar) } ti, err := c.schema.GetTable(root.Table) if err != nil { return 0, err } jt, array, err := jsn.Tree(insert) if err != nil { return 0, err } c.w.WriteString(`WITH `) quoted(c.w, ti.Name) c.w.WriteString(` AS (WITH "input" AS (SELECT {{`) c.w.WriteString(root.ActionVar) c.w.WriteString(`}}::json AS j) INSERT INTO `) c.w.WriteString(ti.Name) io.WriteString(c.w, ` (`) c.renderInsertUpdateColumns(qc, w, jt, ti) io.WriteString(c.w, `)`) c.w.WriteString(` SELECT `) c.renderInsertUpdateColumns(qc, w, jt, ti) c.w.WriteString(` FROM input i, `) if array { c.w.WriteString(`json_populate_recordset`) } else { c.w.WriteString(`json_populate_record`) } c.w.WriteString(`(NULL::`) c.w.WriteString(ti.Name) c.w.WriteString(`, i.j) t RETURNING *) `) return 0, nil } func (c *compilerContext) renderInsertUpdateColumns(qc *qcode.QCode, w *bytes.Buffer, jt map[string]interface{}, ti *DBTableInfo) (uint32, error) { i := 0 for _, cn := range ti.ColumnNames { if _, ok := jt[cn]; !ok { continue } if i != 0 { io.WriteString(c.w, `, `) } c.w.WriteString(cn) i++ } return 0, nil } func (c *compilerContext) renderUpdate(qc *qcode.QCode, w *bytes.Buffer, vars Variables) (uint32, error) { root := &qc.Selects[0] update, ok := vars[root.ActionVar] if !ok { return 0, fmt.Errorf("Variable '%s' not defined", root.ActionVar) } ti, err := c.schema.GetTable(root.Table) if err != nil { return 0, err } jt, array, err := jsn.Tree(update) if err != nil { return 0, err } c.w.WriteString(`WITH `) quoted(c.w, ti.Name) c.w.WriteString(` AS (WITH "input" AS (SELECT {{`) c.w.WriteString(root.ActionVar) c.w.WriteString(`}}::json AS j) UPDATE `) c.w.WriteString(ti.Name) io.WriteString(c.w, ` SET (`) c.renderInsertUpdateColumns(qc, w, jt, ti) c.w.WriteString(`) = (SELECT `) c.renderInsertUpdateColumns(qc, w, jt, ti) c.w.WriteString(` FROM input i, `) if array { c.w.WriteString(`json_populate_recordset`) } else { c.w.WriteString(`json_populate_record`) } c.w.WriteString(`(NULL::`) c.w.WriteString(ti.Name) c.w.WriteString(`, i.j) t)`) io.WriteString(c.w, ` WHERE `) if err := c.renderWhere(root, ti); err != nil { return 0, err } io.WriteString(c.w, ` RETURNING *) `) return 0, nil } func (c *compilerContext) renderDelete(qc *qcode.QCode, w *bytes.Buffer, vars Variables) (uint32, error) { root := &qc.Selects[0] ti, err := c.schema.GetTable(root.Table) if err != nil { return 0, err } c.w.WriteString(`DELETE FROM `) c.w.WriteString(ti.Name) io.WriteString(c.w, ` WHERE `) if err := c.renderWhere(root, ti); err != nil { return 0, err } io.WriteString(c.w, ` RETURNING *) `) return 0, nil } func quoted(w *bytes.Buffer, identifier string) { w.WriteString(`"`) w.WriteString(identifier) w.WriteString(`"`) }