// checkDatabaseName checks whether the given TableName is unambiguous
// within this source and if it is, qualifies the missing database name.
func (src *dataSourceInfo) checkDatabaseName(tn parser.TableName) (parser.TableName, error) {
found := false
if tn.DatabaseName == "" {
// No database name yet. Try to find one.
for name := range src.sourceAliases {
if name.TableName == tn.TableName {
if found {
return parser.TableName{}, fmt.Errorf("ambiguous source name: %q", tn.TableName)
}
tn.DatabaseName = name.DatabaseName
found = true
}
}
if !found {
return parser.TableName{}, fmt.Errorf("source name %q not found in FROM clause", tn.TableName)
}
return tn, nil
}
// Database given. Check that the name is unambiguous.
if _, ok := src.sourceAliases[tn]; ok {
if found {
return parser.TableName{}, fmt.Errorf("ambiguous source name: %q (within database %q)",
tn.TableName, tn.DatabaseName)
}
found = true
}
if !found {
return parser.TableName{}, fmt.Errorf("table %q not selected in FROM clause", &tn)
}
return tn, nil
}
