Incorrect handling of string array insertion into float_vector field

[PavelShilin89]

Description:

When creating a table with a float_vector field and attempting to insert a string representation of an array into this field, an error occurs when executing a KNN query. Instead of a more clear error indicating that the data format is incorrect (string instead of a numeric array), the system returns an “Undefined array key 0” message.

Expected result:

The system should properly handle cases where data for a float_vector field is inserted in the wrong format and return an informative error indicating the need to use a numeric array instead of a string.

ERROR 1064 (42000): Invalid data format for 'float_vector' field. Expected a numeric array, but received a string.

MRE

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CREATE TABLE knn_test (id BIGINT, model TEXT, vector float_vector)
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INSERT INTO knn_test (id, model, vector) VALUES (1, 'Model_1', '[0.9012, 0.2126, 0.2879, 0.7552]')
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SELECT count(*) FROM knn_test WHERE knn(vector, 10, 1)
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ERROR 1064 (42000) at line 1: Undefined array key 0