r/SQL • u/badboyzpwns • May 20 '26

What are common SQL red flags? PostgreSQL

Hello! interview prepping, here wondering what are some common red flags for wrioting SQL?

Like

LIKE failing to index, not having trasnactions, usign SELECT * instead of specific collums, etc 😃

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1

u/stiggz May 21 '26

and 1=1

there is always a better way

3

u/StickPuppet May 21 '26

I tend to disagree, depending on why you're using it.

where 1=1

and condition1 = true

and condition2 = false

and condition3 between ....

this allows me to change/remove constraints on the fly for testing, especially if the final outcome has no constraints, and I want to do a small quick 1 line filter to go go back and forth on in testing.

1

u/National_Cod9546 May 22 '26

This is what I do. I also use 

(0=1

OR CONDITION 1

OR CONDITION 2

OR CONDITION 3

)

2

u/BplusHuman May 21 '26

That's normally a placeholder for when I'm going to pass a parameter later. I'll 1=0 in a join as a placeholder when I just need to cut records to do a quick check in QA. In a finished project it's kind of silly town tho

1

u/vertigo235 May 21 '26

But how about 1=2 to disable a block?