69 lines
1.7 KiB
Plaintext
69 lines
1.7 KiB
Plaintext
create table parent (
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a int primary key auto_increment,
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b int,
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c int,
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unique(b) using hash,
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index(c)) engine = ndb;
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Warnings:
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Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
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create table child (
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a int primary key auto_increment,
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b int,
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c int,
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unique(b) using hash,
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index(c)) engine = ndb;
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Warnings:
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Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
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alter table child add constraint fkname foreign key (b) references parent(b) on delete restrict on update cascade;
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insert into parent values (1,1,1), (2,2,2);
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insert into child values (1,1,1),(2,2,2);
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begin;
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update parent set b = 1 where a = 1;
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select * from child order by 1,2,3;
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a b c
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1 1 1
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2 2 2
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rollback;
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begin;
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update parent set b = null where a = 1;
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select * from child order by 1,2,3;
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a b c
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1 NULL 1
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2 2 2
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rollback;
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begin;
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update parent set b = 3 where a = 1;
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select * from child order by 1,2,3;
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a b c
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1 3 1
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2 2 2
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rollback;
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delete from child;
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delete from parent;
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alter table child drop foreign key fkname;
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alter table child add constraint fkname foreign key (c) references parent(b) on delete restrict on update cascade;
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insert into parent values (1,1,1),(2,2,2);
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insert into child values (1,1,1),(2,2,2),(3,3,1),(4,4,2);
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begin;
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update parent set b = null where a = 1;
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select * from child order by 1,2,3;
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a b c
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1 1 NULL
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2 2 2
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3 3 NULL
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4 4 2
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rollback;
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begin;
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update parent set b = 3 where a = 1;
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select * from child order by 1,2,3;
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a b c
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1 1 3
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2 2 2
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3 3 3
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4 4 2
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rollback;
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delete from child;
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delete from parent;
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alter table child drop foreign key fkname;
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drop table parent, child;
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