PostgreSQL 字符变化长度限制

# PostgreSQL字符变化长度限制及案例代码

sql
CREATE TABLE example_char (
    id SERIAL PRIMARY KEY,
    name CHAR(10)
);
INSERT INTO example_char (name) VALUES ('John');

sql
CREATE TABLE example_varchar (
    id SERIAL PRIMARY KEY,
    description VARCHAR(255)
);
INSERT INTO example_varchar (description) VALUES ('A variable-length string');

sql
BEGIN;
    -- 假设name字段的长度限制为5
    DO $$ 
    BEGIN 
        INSERT INTO example_char (name) VALUES ('Christopher'); 
    EXCEPTION 
        WHEN VALUE_TOO_LONG THEN 
            -- 超出长度时的处理，这里选择截断字符串
            INSERT INTO example_char (name) VALUES (LEFT('Christopher', 5)); 
    END $$;
COMMIT;