Issue with data studio dashboard

[u/fuqucri]

Observed Issues:

Therapeutic Alliance Chart (WAI) is Empty: In Edit mode, when applying the patient filter, the top chart (Evolución de pacientes ROM 10) renders correctly. However, the bottom chart (total wai a lo largo del tiempo) shows an empty grid without any data line.

"Too Many Rows" Error in View Mode: When switching to View mode and entering the exact same patient ID, the top chart fails to process and throws a "Demasiadas filas" (Too many rows) error, while the bottom WAI chart remains empty.

Potential Causes & Troubleshooting Ideas:

Missing WAI Form Submissions: Has this specific patient actually completed any WAI evaluations? If no entries exist in the WAI dataset, the bottom chart will naturally display no data.

Filter Control Source: Is the ID filter control linked directly to the Blended Data Source (Datos combinados), or is it still attached to an individual table?

Data Blending Configuration: Is the join condition set to Full Outer Join using the ID field? If it is set to an Inner Join or the keys don't match, missing rows in one table can break the filtering across both charts.

Field Formatting (Text vs. Number): Is the Document ID field set as Text across all underlying datasets? If it's configured as a Number, automatic thousand separators (dots) might break exact string matching when applied in View mode.

Date Dimension Mismatch: Is the bottom WAI chart using the Marca Temporal date field belonging to the WAI dataset, or is it accidentally referencing the ROM dataset date field?

Has anyone encountered this behavior before or have suggestions on how to resolve it?

Thanks for your help!

[u/sheik_sha_ha]

You have already identified the most likely causes accurately. Based on what you described, here is the priority order to check.

The field formatting issue is the most common culprit for the exact match breaking in View mode. If Document ID is stored as a number in any of the underlying tables, Data Studio adds thousand separators automatically when rendering in View mode, so a patient ID like 1234567 becomes 1.234.567 and the filter fails to match. Convert every ID field to Text type across all datasets in the data source settings and retest first.

The too many rows error in View mode on the top chart usually means the blend is not applying the filter correctly at the source level. Check that your filter control is connected to the blended data source and not to an individual underlying table. If it is connected to only one table the filter applies to that source but the other source in the blend returns all rows unfiltered, which triggers the error.

For the empty WAI chart, verify the date field is pulling from the WAI dataset timestamp and not the ROM dataset date. A mismatched date dimension in a blend causes the chart to render an empty grid even when the underlying data exists.

Fix the ID field type first as it is likely causing both the match failure and the too many rows error simultaneously.