first commit

qry_update.go

@@ -0,0 +1,100 @@
+// Patial Tech.
+// Author, Ankit Patial
+
+package pgm
+
+import (
+	"context"
+	"strconv"
+	"strings"
+
+	"github.com/jackc/pgx/v5"
+)
+
+type updateQry struct {
+	table     string
+	cols      []string
+	condition []Conditioner
+	args      []any
+	debug     bool
+}
+
+func (t *Table) Update() Update {
+	qb := &updateQry{
+		table: t.Name,
+		debug: t.debug,
+		cols:  make([]string, 0, t.FieldCount),
+		args:  make([]any, 0, t.FieldCount),
+	}
+	return qb
+}
+
+func (q *updateQry) Set(field Field, val any) UpdateClause {
+	col := field.Name()
+	q.cols = append(q.cols, col+"=$"+strconv.Itoa(len(q.args)+1))
+	q.args = append(q.args, val)
+	return q
+}
+
+func (q *updateQry) SetMap(cols map[Field]any) UpdateClause {
+	for k, v := range cols {
+		q.Set(k, v)
+	}
+	return q
+}
+
+func (q *updateQry) Where(cond ...Conditioner) WhereOrExec {
+	q.condition = append(q.condition, cond...)
+	return q
+}
+
+func (q *updateQry) Exec(ctx context.Context) error {
+	_, err := poolPGX.Load().Exec(ctx, q.String(), q.args...)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (q *updateQry) ExecTx(ctx context.Context, tx pgx.Tx) error {
+	_, err := tx.Exec(ctx, q.String(), q.args...)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (q *updateQry) String() string {
+	sb := getSB()
+	defer putSB(sb)
+
+	n := 7 + len(q.table) + 5 // "UPDATE q.table SET
+	for _, col := range q.cols {
+		n += len(col) + 5
+	}
+	if len(q.condition) > 0 {
+		n += 7 + len(q.condition)*5 // WHERE with condition, 5 is just avg small min val
+	}
+	sb.Grow(n)
+
+	// UPDATE
+	sb.WriteString("UPDATE " + q.table + " SET ")
+	sb.WriteString(strings.Join(q.cols, ", "))
+
+	// WHERE
+	if len(q.condition) > 0 {
+		sb.WriteString(" WHERE ")
+		var argIdx int
+		for i, c := range q.condition {
+			argIdx = len(q.args)
+			if i > 0 {
+				sb.WriteString(" AND ")
+			}
+			sb.WriteString(c.Condition(&q.args, argIdx))
+		}
+	}
+
+	return sb.String()
+}