For application compatibility reasons MySQL converts "<autoincrement_column> IS NULL"
predicates to "<autoincrement_column> = LAST_INSERT_ID()" in the first SELECT following an
INSERT regardless of whether they're top level predicates or not. This causes wrong and
obscure results when these predicates are combined with others on the same columns. Fixed
by only doing the transformation on a single top-level predicate if a special SQL mode is
turned on (sql_auto_is_null).
Also made sql_auto_is_null off by default.
per-file comments:
mysql-test/r/func_isnull.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test result updated
mysql-test/t/func_isnull.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test case added
sql/mysqld.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
sql_auto_is_null now is OFF by default.
sql/sql_select.cc
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
remove_eq_conds() split in two parts - one only checks the upper condition,
the req_remove_eq_conds() recursively checks all the condition tree.
mysql-test/extra/rpl_tests/rpl_insert_id.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
mysql-test/r/mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/mysqlbinlog2.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/odbc.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/query_cache.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/r/user_var-binlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_row_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_insert_id.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_row_mysqlbinlog.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/suite/rpl/r/rpl_sp.result
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
result updated
mysql-test/t/odbc.test
Bug#41371 Select returns 1 row with condition "col is not null and col is null"
test fixed (set the sql_auto_is_null variable)
To make MySQL compatible with some ODBC applications, you can find
the AUTO_INCREMENT value for the last inserted row with the following query:
SELECT * FROM tbl_name WHERE auto_col IS NULL.
This is done with a special code that replaces 'auto_col IS NULL' with
'auto_col = LAST_INSERT_ID'.
However this also resets the LAST_INSERT_ID to 0 as it uses it for a flag
so as to ensure that only the first SELECT ... WHERE auto_col IS NULL
after an INSERT has this special behaviour.
In order to avoid resetting the LAST_INSERT_ID a special flag is introduced
in the THD class. This flag is used to restrict the second and subsequent
SELECTs instead of LAST_INSERT_ID.
