fix(DBI-1096 - clickhouse destination connector): Honor nullability for destination_type overrides in normalize - #4783
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| return nil, fmt.Errorf("error while converting column type to ClickHouse type: %w", err) | ||
| } | ||
| } else if (tableSchema.NullableEnabled || columnNullableEnabled) && column.Nullable && !colType.IsArray() { | ||
| } else if (tableSchema.NullableEnabled || columnNullableEnabled) && column.Nullable && !colType.IsArray() && |
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afaiu tableSchema.NullableEnabled is kind of a global flag whether we want to have nullable fields at the destination at all (regardless of source column nullability)
so, I think it should be tableSchema.NullableEnabled && columnNullableEnabled, no?
if tableSchema.NullableEnabled is false, it means that none of the destination columns can be nullable
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ah
we have schema.NullableEnabled and column.NullableEnabled
seems like we can put false on the schema lvl and override on the column lvl..
so OR is correct here I guess
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seems like we can put false on the schema lvl and override on the column lvl..
Exactly, at least this is how I interpret it.
| } | ||
| } else if (schema.NullableEnabled || columnNullableEnabled) && column.Nullable && !colType.IsArray() && | ||
| !strings.HasPrefix(clickHouseType, "Nullable(") { | ||
| // mirror the table DDL: a nullable-enabled column created as Nullable(...) must also be |
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should we move it to the helper then?
if it's exactly the same condition as in flow/connectors/clickhouse/normalize.go.
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It's the same condition today but JSON extraction function and DDL are different enough IMO as to maybe make us stumble upon different conditions in future changes.
🔄 Flaky Test DetectedAnalysis: All 88 failures are timeout collateral from ✅ Automatically retrying the workflow |
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With a table mapping column setting both a
destination_typeoverride and nullability (table- or column-levelnullable_enabled), the DDL generator creates the destination column as Nullable(), but the normalize query still extracted it as plain . JSONExtract to a non-nullable type turns JSON nulls into the type's default, so NULL values silently landed as0," ", etc. instead of NULL.This PR makes the normalize query generator mirror the DDL:
Part of: https://linear.app/clickhouse/issue/DBI-1096
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