默认为列“xxxx”不能自动转换为在Postgres DB中键入布尔值

Question

我想从brs.parts表中的字符更改为布尔值。 该列的数据为Y/N至今。 我使用下面的命令

ALTER TABLE brs.parts ALTER COLUMN is_dpm_scanned TYPE BOOLEAN USING is_dpm_scanned::BOOLEAN 

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但我收到以下错误：

*********错误**********

ERROR: default for column "is_dpm_scanned" cannot be cast automatically to type boolean 
SQL state: 42804 

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表定义为：

CREATE TABLE brs.parts (
    id serial NOT NULL PRIMARY KEY, 
    webcrt_part_id INTEGER, 
    event_id INTEGER, 
    webcrt_job_id INTEGER, 
    incoming_serial_number CHARACTER VARYING(256), 
    outgoing_serial_number CHARACTER VARYING(256), 
    part_number CHARACTER VARYING(256), 
    tag_number NUMERIC, 
    is_dpm_scanned CHARACTER VARYING(1) DEFAULT 'N'::CHARACTER VARYING, 
    current_operation_id INTEGER, 
    creation_date DATE, 
    created_by CHARACTER VARYING(20) NOT NULL, 
    last_updated_date DATE, 
    last_updated_by CHARACTER VARYING(20) NOT NULL, 
    is_delete CHARACTER VARYING(1) DEFAULT 'N'::CHARACTER VARYING 
); 

Answer 1

你必须改变类型之前下降默认约束：

ALTER TABLE parts 
    ALTER COLUMN is_dpm_scanned DROP DEFAULT, 
    ALTER COLUMN is_dpm_scanned TYPE BOOLEAN USING is_dpm_scanned::BOOLEAN, 
    ALTER COLUMN is_dpm_scanned SET DEFAULT FALSE; 

参见：Changing a column from string to string array in postgresql。