![\"\"](\"https:\/\/i0.wp.com\/kiusi.com\/wp-content\/uploads\/2023\/04\/ORA-00918-01.jpg?ssl=1\")
<\/a><\/figure>\n<\/div>\n\n\nWhen creating a Master Detail - Drill Down page, both pages are created fine, but when I want to edit a master page record by clicking on the pencil icon, the following error is displayed, \"ORA-00918: ambiguously defined column\".<\/strong><\/p>\n\n\n Reviewing the debugging of the page I can see that APEX indicates that the statement generating the error is:<\/p>\n\n\n\n Analyzing the SQL statement, my EDU_MATRICULAS table has a column called TOTAL, and when creating the master-detail of type Drill Down or Expanded as shown in Spanish, it generates three additional columns, one of which is (count(*)over()) \u201cTOTAL\u201d<\/em> which, as we can see, is also called TOTAL.<\/p>\n\n\n\n There are two solutions, one would be to rename the column of the table from TOTAL to TOTAL_MAT, but that implies changes at database level and if we are already using the column in other pages it can generate problems and errors.<\/p>\n\n\n\n Note: It is better, after this, not to create columns in our table that are only called TOTAL, but something more concrete, since APEX uses that name to create the record count.<\/p>\n\n\n\n So to solve this, what we can do is to give an ALIAS name to our TOTAL column.<\/p>\n\n\n\n To do this we go to the detail page, select the Form type region, and then in Source instead of showing the EDU_MATRICULAS table, we will select SQL Query:<\/p>\n\n\n\n All the columns of the table will be displayed:<\/p>\n\n\n\n We place an alias to the \"TOTAL\" column as \"TOTAL_MAT\".<\/p>\n\n\n<\/a><\/figure>\n<\/div>\n\n\n- error_statement: select i.*\r\n from (\r\nselect \"MAT_ID\",\"ALU_ID\",\"FECHA\",\"USUARIO\",\"OBSERVACIONES\",\"TOTAL\",(lead(\"MAT_ID\",1)over(order by null)) \"NEXT_1\",(lag(\"MAT_ID\",1)over(order by null)) \"PREV_1\",(row_number()over(order by null)) \"ROWN\",(count(*)over()) \"TOTAL\"\r\nfrom ((\r\nselect \/*+ qb_name(apex$inner) *\/d.\"MAT_ID\",d.\"ALU_ID\",d.\"FECHA\",d.\"USUARIO\",d.\"OBSERVACIONES\",d.\"TOTAL\" from (\r\nselect x.* from \"EDU_MATRICULAS\" x \r\n\r\n) d\r\n\r\n )) i \r\n\r\n) i where 1=1 \r\n\r\n\r\n and \"MAT_ID\"=:apex$f1\r\n<\/code><\/pre>\n\n\n<\/a><\/figure>\n<\/div>\n\n\nselect MAT_ID,\n ALU_ID,\n FECHA,\n TOTAL,\n USUARIO,\n OBSERVACIONES\n from EDU_MATRICULAS\r<\/code><\/pre>\n\n\n\n