postgreSQLでVARCHARとCHARを試した

バージョン：psql (PostgreSQL) 11.1

(n)なしでCHAR

postgres=# create table tmp1 (name CHAR);
CREATE TABLE
postgres=# insert into tmp1 values ('aaa');
ERROR:  value too long for type character(1)
postgres=# insert into tmp1 values ('aa');
ERROR:  value too long for type character(1)
postgres=# insert into tmp1 values ('a');
INSERT 0 1
postgres=#

(n)なしでVARCHAR

postgres=# create table tmp2 (name VARCHAR);
CREATE TABLE
postgres=# insert into tmp2 values ('aaa');
INSERT 0 1
postgres=#

CHAR(1)にしてみる

postgres=# create table tmp3 (name CHAR(1));
CREATE TABLE
postgres=# insert into tmp3 values ('aaa');
ERROR:  value too long for type character(1)
postgres=# insert into tmp3 values ('aa');
ERROR:  value too long for type character(1)
postgres=# insert into tmp3 values ('a');
INSERT 0 1
postgres=#

VARCHAR(1)にしてみる

postgres=# create table tmp4 (name VARCHAR(1));
CREATE TABLE
postgres=# insert into tmp4 values ('aaa');
ERROR:  value too long for type character varying(1)
postgres=# insert into tmp4 values ('aa');
ERROR:  value too long for type character varying(1)
postgres=# insert into tmp4 values ('a');
INSERT 0 1
postgres=#