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…inality type string
When chaining .lowCardinality().nullable() or .nullable().lowCardinality(),
the SDK correctly produces the type string LowCardinality(Nullable(X)).
However, it also set nullable: true in the column modifiers metadata.
The backend checks modifiers.nullable and wraps the type with Nullable()
if the type string doesn't start with 'Nullable('. Since
LowCardinality(Nullable(X)) starts with 'LowCardinality(', the backend
would double-wrap it into Nullable(LowCardinality(Nullable(X))), which
ClickHouse rejects.
Fix: omit the nullable modifier flag when nullable is already encoded
inside the LowCardinality type string wrapper.
Co-authored-by: Amp <amp@ampcode.com>
Amp-Thread-ID: https://ampcode.com/threads/T-019d247b-1dfc-764a-ae09-697511e5209f
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tested that deployment works |
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Problem
When chaining
t.string().lowCardinality().nullable(), the SDK correctly produces the ClickHouse type stringLowCardinality(Nullable(String)), but also setsnullable: truein the column modifiers metadata.The backend (
datasource_schema.py) checks whether to wrap the type withNullable()by testing if the type string starts with"Nullable(". SinceLowCardinality(Nullable(String))starts with"LowCardinality(", the check passes and the backend wraps it again, producingNullable(LowCardinality(Nullable(String)))— which ClickHouse rejects.Fix
Omit the
nullablemodifier flag from column metadata when nullable is already encoded inside theLowCardinality(...)type string wrapper. This applies to both chaining orders:.lowCardinality().nullable().nullable().lowCardinality()The type string itself remains correct (
LowCardinality(Nullable(X))), and the backend no longer redundantly wraps it.