SQLite raises “datatype mismatch” when your statement tries to compare, insert, or join values whose declared types or affinities are incompatible.
SQLite “datatype mismatch” means the value’s type conflicts with the target column or expression—e.g., comparing TEXT to INTEGER. Align data types by CAST-ing the value, altering the column type, or correcting the predicate to fix the error.
datatype mismatch
The SQLite error “datatype mismatch” occurs when the engine cannot reconcile the declared type affinity of a column or expression with the value supplied in an INSERT, UPDATE, comparison, or JOIN clause.
SQLite is loosely typed, but some operations—UNIQUE checks, CHECK constraints, strict tables, and comparisons—require compatible affinities.
When an incompatible value is provided, SQLite stops execution and throws this error.
A mismatch happens if an INTEGER column receives a non-numeric string, or a TEXT column is compared to a numeric literal without explicit casting.
Joins on keys stored as different types can also trigger the error.
Strict tables introduced in SQLite 3.37 enforce stronger type rules, so legacy data inserted into those tables often fails with “datatype mismatch.”
First, locate the offending column or expression by checking the statement in the error log.
Ensure the value’s type matches the column’s affinity, or convert it with CAST().
If the schema is wrong, ALTER TABLE to change the column type or rebuild the table with the correct affinity.
Where comparisons fail, CAST both sides to a common type or adjust query parameters.
Attempting to insert the string “ABC” into an INTEGER PRIMARY KEY causes an immediate mismatch; cast or sanitize the value to an integer.
Joining order_id (INTEGER) to order_id (TEXT) across tables triggers the error. Align both columns to INTEGER or CAST in the JOIN predicate.
Storing ISO date strings in INTEGER timestamp columns fails under strict mode.
Convert the text date to epoch seconds or change the column affinity to TEXT.
Define columns with the correct affinity from the start and document expected formats. Validate and cast user input before executing SQL.
Enable PRAGMA strict=ON in development to catch mismatches early, and use Galaxy’s AI copilot to flag type inconsistencies during code review.
“no such column” appears when a referenced field is misspelled; fix the identifier.
“constraint failed” arises when UNIQUE or CHECK rules are violated; review the constraint logic.
SQLite uses dynamic typing with affinity, but strict tables and certain operations enforce stronger type rules that can trigger “datatype mismatch.”
No pragma suppresses the error; you must supply compatible types or adjust the schema.
Newer SQLite versions tighten type checks, especially with strict tables, revealing latent mismatches in legacy code.
Galaxy’s AI copilot highlights column affinities and flags potential mismatches while you type, preventing runtime failures in production.
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