ORA-01789: query block has incorrect number of result columnsYou may see this error in the following situation:
create table test1_1789 (Table test2_1789 contains one column too many.
create table test2_1789 (
select * from test1_1789
select * from test2_1789;
ORA-01789: query block has incorrect number of result columns
This fact becomes a problem because we are using * as column list specifier and it can be avoided by specifying an explicit list of columns common to both tables.
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