TRIM(), UPPER() & LOWER()

These are the DAX equivalents of Power Query's Text.Trim(), Text.Upper() & Text.Lower() — with one real difference in what TRIM() actually removes.

TRIM(text)
UPPER(text)
LOWER(text)

UPPER() and LOWER()

UPPER("active")
LOWER("ACTIVE")

UPPER("active") -> "ACTIVE"
LOWER("ACTIVE") -> "active"

These behave exactly as expected, and exactly like their Power Query counterparts — the only real subtlety with case conversion is using it for comparison rather than display, covered below.

TRIM() Also Collapses Internal Spaces

TRIM("  Widget   Sales  ")

"  Widget   Sales  " -> "Widget Sales"

DAX's TRIM() mirrors Excel's TRIM(): it removes leading and trailing spaces, and collapses every internal run of multiple spaces down to a single space. This is different from Power Query's Text.Trim(), which only touches the leading and trailing ends — internal spaces, however many there are, pass through completely unchanged.

The same messy source text produces two different-length results depending on which layer cleans it: TRIM() in DAX quietly fixes a double space typed between two words; Text.Trim() in Power Query leaves it exactly as it was.

"  Widget   Sales  "
TRIM(...)       -> "Widget Sales"     (11 chars, one space between words)
Text.Trim(...)  -> "Widget   Sales"   (14 chars, all 3 internal spaces survive)

UPPER() / LOWER() for Comparison, Not Just Display

Status Match = LOWER([Status]) = "active"

DAX text comparisons are case-sensitive by default, same as Power Query — converting both sides to a consistent case before comparing is the standard fix.

Common Mistakes

Assuming TRIM() Only Touches the Ends, Like Text.Trim()

Porting a value cleaned with Text.Trim() in Power Query into a DAX calculated column and re-cleaning it with TRIM() can produce a shorter result than expected — any internal double space that survived Text.Trim() gets collapsed by TRIM(), which may or may not be desired depending on whether that internal spacing was meaningful.

Expecting Text.Trim() to Catch an Internal Double Space

The reverse mistake: assuming Power Query already normalized internal spacing because a value "went through Text.Trim()" — it didn't touch anything except the two ends.

Overwriting Original Case When Only Comparison Needed It

Applying UPPER() or LOWER() directly to a calculated column meant for display permanently destroys the original casing — convert case only inside the comparison expression itself if the original value still needs to display normally.

Best Practices

• Use TRIM() when internal double-spacing genuinely needs cleaning up, not just leading/trailing whitespace.
• Don't assume a value is already fully cleaned just because it passed through the other language's trim function — the two aren't equivalent.
• Convert case only inside a comparison expression (LOWER([Status]) = "active"), not as a standing transformation, when the original casing still needs to display.

Next Steps

• Text.Trim(), Text.Upper() & Text.Lower()
• LEFT(), RIGHT() & MID()
• DAX Function Reference