super-graph/psql/insert.go

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2019-09-05 06:09:56 +02:00
package psql
import (
"bytes"
"errors"
"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]
c.w.WriteString(`WITH `)
c.w.WriteString(root.Table)
c.w.WriteString(` AS (`)
if _, err := c.renderInsert(qc, w, vars); err != nil {
return 0, err
}
c.w.WriteString(`) `)
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["insert"]
if !ok {
return 0, errors.New("Variable 'insert' not defined")
}
jt, array, err := jsn.Tree(insert)
if err != nil {
return 0, err
}
c.w.WriteString(`WITH input AS (SELECT {{insert}}::json AS j) INSERT INTO `)
c.w.WriteString(root.Table)
io.WriteString(c.w, " (")
c.renderInsertColumns(qc, w, jt)
io.WriteString(c.w, ")")
c.w.WriteString(` SELECT `)
c.renderInsertColumns(qc, w, jt)
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(root.Table)
c.w.WriteString(`, i.j) t RETURNING * `)
return 0, nil
}
func (c *compilerContext) renderInsertColumns(qc *qcode.QCode, w *bytes.Buffer,
jt map[string]interface{}) (uint32, error) {
ti, err := c.schema.GetTable(qc.Selects[0].Table)
if err != nil {
return 0, err
}
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
}