Hi, Alexey! Looks good, thanks! See few comments below, then ok to push! On Aug 30, Alexey Botchkov wrote:

revision-id: 49499250c04b631bd908945b7c59d6affaeb2703 (mariadb-10.2.1-9-g4949925) parent(s): 08683a726773f8cdf16a4a3dfb3920e5f7842481 committer: Alexey Botchkov timestamp: 2016-08-30 16:43:05 +0400 message:

MDEV-10421 duplicate CHECK CONSTRAINTs.

mysql_prepare_create_table fixed so it doesn't let duplicating constraint names. Syntax for CONSTRAINT IF NOT EXISTS added and handled in mysql_alter_table.

diff --git a/sql/field.h b/sql/field.h index 13a0e91..7b271b0 100644 --- a/sql/field.h +++ b/sql/field.h @@ -606,6 +606,7 @@ class Virtual_column_info: public Sql_alloc /* Flag indicating that the field is physically stored in the database */ bool stored_in_db; bool utf8; /* Already in utf8 */ + bool create_if_not_exists;

You apparently forgot to remove create_if_not_exists. It doesn't seem to be used anywhere.

/* The expression to compute the value of the virtual column */ Item *expr_item; /* Text representation of the defining expression */ diff --git a/sql/sql_table.cc b/sql/sql_table.cc index e745fe8..c120fbc 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -6130,6 +6146,38 @@ handle_if_exists_options(THD *thd, TABLE *table, Alter_info *alter_info) } #endif /*WITH_PARTITION_STORAGE_ENGINE*/

+ /* ADD CONSTRAINT IF NOT EXISTS. */ + { + List_iterator<Virtual_column_info> it(alter_info->check_constraint_list); + Virtual_column_info *check; + TABLE_SHARE *share= table->s; + uint c; + while ((check=it++)) + { + if (!check->flags /* & Alter_info::CHECK_CONSTRAINT_IF_NOT_EXISTS */ &&

why is that? because CHECK_CONSTRAINT_IF_NOT_EXISTS is the only possible flag now? I'd still prefer it a bit more future-proof, better to check the flag here.

+ check->name.length) + continue; + check->flags= 0; + for (c= share->field_check_constraints; + c < share->table_check_constraints ; c++) + { + Virtual_column_info *dup= table->check_constraints[c]; + if (dup->name.length == check->name.length && + my_strcasecmp(system_charset_info, + check->name.str, dup->name.str) == 0) + { + push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_DUP_CONSTRAINT_NAME, ER_THD(thd, ER_DUP_CONSTRAINT_NAME), + "CHECK", check->name.str); + it.remove(); + if (alter_info->check_constraint_list.elements == 0) + alter_info->flags&= ~Alter_info::ALTER_ADD_CHECK_CONSTRAINT; + + break; + } + } + } + } DBUG_VOID_RETURN; }

You seem to forgot to add #define ER_FK_DUP_NAME ER_DUP_CONSTRAINT_NAME to mysql.h. Regards, Sergei Chief Architect MariaDB and security@mariadb.org