// Prepare returns the result types of the given statement. pinfo may
// contain partial type information for placeholders. Prepare will
// populate the missing types. The column result types are returned (or
// nil if there are no results).
func (e *Executor) Prepare(
query string,
session *Session,
pinfo parser.PlaceholderTypes,
) ([]ResultColumn, error) {
if log.V(2) {
log.Infof(session.Ctx(), "preparing: %s", query)
} else if traceSQL {
log.Tracef(session.Ctx(), "preparing: %s", query)
}
stmt, err := parser.ParseOne(query, parser.Syntax(session.Syntax))
if err != nil {
return nil, err
}
if err = pinfo.ProcessPlaceholderAnnotations(stmt); err != nil {
return nil, err
}
protoTS, err := isAsOf(&session.planner, stmt, e.ctx.Clock.Now())
if err != nil {
return nil, err
}
session.planner.resetForBatch(e)
session.planner.semaCtx.Placeholders.SetTypes(pinfo)
session.planner.evalCtx.PrepareOnly = true
// Prepare needs a transaction because it needs to retrieve db/table
// descriptors for type checking.
txn := client.NewTxn(session.Ctx(), *e.ctx.DB)
txn.Proto.Isolation = session.DefaultIsolationLevel
session.planner.setTxn(txn)
defer session.planner.setTxn(nil)
if protoTS != nil {
session.planner.asOf = true
defer func() {
session.planner.asOf = false
}()
setTxnTimestamps(txn, *protoTS)
}
plan, err := session.planner.prepare(stmt)
if err != nil {
return nil, err
}
if plan == nil {
return nil, nil
}
cols := plan.Columns()
for _, c := range cols {
if err := checkResultDatum(c.Typ); err != nil {
return nil, err
}
}
return cols, nil
}
// Prepare returns the result types of the given statement. pinfo may
// contain partial type information for placeholders. Prepare will
// populate the missing types. The column result types are returned (or
// nil if there are no results).
func (e *Executor) Prepare(
ctx context.Context,
query string,
session *Session,
pinfo parser.PlaceholderTypes,
) ([]ResultColumn, error) {
stmt, err := parser.ParseOne(query, parser.Syntax(session.Syntax))
if err != nil {
return nil, err
}
if err = pinfo.ProcessPlaceholderAnnotations(stmt); err != nil {
return nil, err
}
session.planner.resetForBatch(e)
session.planner.semaCtx.Placeholders.SetTypes(pinfo)
session.planner.evalCtx.PrepareOnly = true
// Prepare needs a transaction because it needs to retrieve db/table
// descriptors for type checking.
txn := client.NewTxn(ctx, *e.ctx.DB)
txn.Proto.Isolation = session.DefaultIsolationLevel
session.planner.setTxn(txn)
defer session.planner.setTxn(nil)
plan, err := session.planner.prepare(stmt)
if err != nil {
return nil, err
}
if plan == nil {
return nil, nil
}
cols := plan.Columns()
for _, c := range cols {
if err := checkResultDatum(c.Typ); err != nil {
return nil, err
}
}
return cols, nil
}