public override IEnumerable <Command> HandleAlterCollation(Identifier fieldName, Identifier relationName, IHasCollation collation, IHasCollation otherCollation)
{
if (collation.CollationId != null && otherCollation.CollationId != collation.CollationId)
{
throw new NotSupportedOnFirebirdException($"Altering collation on the field is not supported ({relationName}.{fieldName}).");
}
yield break;
}
public virtual IEnumerable <Command> HandleAlterCollation(Identifier fieldName, Identifier relationName, IHasCollation collation, IHasCollation otherCollation)
{
if (collation.CollationId != null && otherCollation.CollationId != collation.CollationId)
{
var systemTableName = relationName != null ? "RDB$RELATION_FIELDS" : "RDB$FIELDS";
var builder = new StringBuilder();
builder
.Append($"UPDATE {systemTableName}")
.AppendLine()
.Append($" SET RDB$COLLATION_ID = {collation.CollationId}")
.AppendLine()
.Append($"WHERE RDB$FIELD_NAME = '{fieldName}'");
if (relationName != null)
{
builder.Append($" AND RDB$RELATION_NAME = '{relationName}'");
}
yield return(new Command().Append(builder.ToString()));
}
}
