当你遇到 PostgreSQL 报错“null value in column "id" violates not-null constraint”时,这表示你尝试在 "id" 列中插入或更新一个 NULL 值,但该列被设置为非空(NOT NULL)约束。要解决这个问题,你可以按照以下步骤进行: 确认"id"列的非空约束: 首先,确认你的数据库表结构中 "id" 列确实被设置为非空。
ERROR: null value in column "a" violates not-null constraint DETAIL: Failing row contains (null, 3). test=# select * from tbl_null; a | b ---+--- 1 | 1 2 | (2 rows)*/ 2.NOT NULL约束增加 已存在的字段设置NOT NULL约束前必须先删除为NULL的数据行。 /*test=# alter table tbl_...
Null is: null Understanding NULL in PostgreSQL In PostgreSQL, NULL means no value. In other words, the NULL column does not have any value. It does not equal 0, empty string, or spaces. The NULL value cannot be tested using any equality operator like “=” “!=” etc. There are some...
test=# create table tbl_null (a int not null,b varchar(12)); CREATE TABLE test=# insert into tbl_null (a,b) values(1,'1'); INSERT 0 1 test=# insert into tbl_null (a) values(2); INSERT 0 1 test=# insert into tbl_null (b) values('3'); ERROR: null value in column "a...
PostgreSQL存储null值的方法 使用pageinspact工具来观察null是如何存储的。执行下面的测试: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 postgres=#createtablet(iint, jint, kint); CREATETABLE postgres=#insertintotvalues(8,1,6); INSERT0 1 ...
; SQL []; ERROR: null value in column "person_id" violates not-null constraint 详细:Failing row contains (null, 小兰, 2, 重庆, 2017-06-04).; nested exception is org.postgresql.util.PSQLException: ERROR: null value in column "person_id" violates not-null constraint ...
CREATE[ORREPLACE]FUNCTIONname([[argmode][argname]argtype[{DEFAULT|=}default_expr][,...]])[RETURNSrettype|RETURNSTABLE(column_name column_type[,...])]{LANGUAGElang_name|TRANSFORM{FORTYPEtype_name}[,...]|WINDOW|IMMUTABLE|STABLE|VOLATILE|[NOT]LEAKPROOF|CALLEDONNULLINPUT|RETURNSNULLONNULLINPUT|...
UPDATEtable_nameSETcolumn1=value1,column2=value2...,columnN=valueNWHERE[condition];UPDATEemploySETage=23,salary=11000WHEREid=1; 4.删除数据(DELETE语句)DELETE语句用于从表中删除现有记录。 “WHERE”子句用于指定删除所选记录的条件,如是不指定条件则将删除所有记录。 语法...
COPY table_name [ ( column [, ...] ) ] FROM { 'filename' | STDIN } [ WITH ] [ BINARY ] [ OIDS ] [ DELIMITER [ AS ] 'delimiter' ] [ NULL [ AS ] 'null string' ] [ CSV [ QUOTE [ AS ] 'quote' ] [ ESCAPE [ AS ] 'escape' ] [ FORCE NOT NULL column [, ...] ...
ERROR:nullvalueincolumn"b" violatesnot-nullconstraintDETAIL: Failing rowcontains(1,null,5). 2.删除主键约束 test=#altertabletbl_primarydropconstraintpk_tbl_primary_a_b ;ALTERTABLE 3.增加主键约束 向已存在的表中增加主键约束就必须考虑已存在的数据不是唯一的,或者有可能是NULL,此时增加主键约束就会失败...