to execute the code : https://dbfiddle.uk/?rdbms=oracle_21&fiddle=69131953cf61459b64092025737d79b7
I have a object that has several field.
And I want to say that a field can have only certain values.
I tried to do that the same way I would do it with a table
create type oa as object(
a VARCHAR2(59) constraint cta check(a in ('a1','a2' ))
)
ORA-24344: success with compilation error
I have tried to create a table and say that my object has the same fields
CREATE TABLE ta(
a VARCHAR2(59) constraint cta check(a in ('a1','a2' ))
)
Create type oa2 as ta%rowtype
ORA-24344: success with compilation error
It doesn't work either.
You cannot; constraints can only be applied to tables or views.
From the constraint documentation:
Constraint clauses can appear in the following statements:
CREATE TABLE (see CREATE TABLE)
ALTER TABLE (see ALTER TABLE)
CREATE VIEW (see CREATE VIEW)
ALTER VIEW (see ALTER VIEW)
As an alternative, you can declare the type as:
CREATE TYPE oa as object(
a VARCHAR2(59)
);
Then declare an object-derived table with an added CHECK constraint:
CREATE TABLE oat OF oa (
CONSTRAINT oat_chk CHECK (a in ('a1', 'a2'))
);
Then:
INSERT INTO oat VALUES (oa('a1'));
INSERT INTO oat (a) VALUES ('a1');
works but:
INSERT INTO oat VALUES (oa('b1'));
INSERT INTO oat (a) VALUES ('b1');
Violates the check constraint.
db<>fiddle here
Related
I have the below Nested table created :
create or replace TYPE access_t AS OBJECT (
AccessID VARCHAR2(50),
Eligibility char(1)
);
/
create or replace TYPE Access_tab IS TABLE OF access_t;
/
create or replace TYPE add_t AS OBJECT (
city VARCHAR2(100),
state VARCHAR2(100),
zip VARCHAR2(10),
APOINTSARRAY Access_tab )
;
/
create or replace TYPE add_tab IS TABLE OF add_t;
/
CREATE TABLE RQST_STATUS
( RQST_ID NUMBER,
ADDRESS add_tab
)
NESTED TABLE ADDRESS STORE AS RQST_STATUS_ADDRESS
( NESTED TABLE APOINTSARRAY STORE AS RQST_STATUS_AP)
;
If i need to change ADDRESS type to new_add_tab with some additional columns instead of add_tab , Can i just use ALTER TABLE .. MODIFY .. command ?
I am getting ORA-00922 or ORA-22913 errors . I cannot change the type directly because it is used somewhere else too. Also, the table is already loaded with data.
Please suggest.
You can do that but you have to alter the TYPE not the TABLE.
Check the documentation ALTER TYPE Statement: alter_method_spec
Most important is the CASCADE key word.
Examples:
ALTER TYPE access_t ADD ATTRIBUTE NEW_Eligibility INTEGER CASCADE;
ALTER TYPE access_t DROP ATTRIBUTE Eligibility CASCADE;
ALTER TYPE access_t MODIFY ATTRIBUTE AccessID VARCHAR2(100) CASCADE;
Here is a step-by-step description of my suggestion. It might not be the most elegant, but I think that it would be best for you to have something you can fully understand (as opposed to an obscure trick).
Also, and since I don't really know what kind of changes you need to do for the internal table, I'm leaving the maximal flexibility for you to do any change you may wish to do.
Let's call your table T1 that contains a columns C_T which is your internal table.
The internal table contains columns C_1, C-2 and C_3, and you want the new structure for the record to be D_1, D_2, D_3, D_4 and D_5, where the mapping is:
C_1 -> D_5,
C_2 -> D_1,
C_3 -> D_2,
{new} -> D_3,
{new} -> D_4.
Create a tempo table TEMPO_T with a column SOURCE_ROWID (varchar2(64)) and the new columns D_1,..., D5.
Write a small anonymous block having a cursor that selects the ROWID of each row of table T1 and all the records within the internal table in column C_T (order by ROWID). The result would look like (this is just an example of course):
ROWID C_1 C_2 C_2
wwereeedffff 1 a ww
wwereeedffff 2 b xx
wwereeedffff 7 l yy
ertrtrrrtrrr 5 d PP
ertrtrrrtrrr 99 h mm
...
[Note: The use of ROWID is under the assumption that you don't have a column that can serve as a unique identifier for each row in table T1; if there is such column - one defined as UNIQUE INDEX - you can use that field instead]
Having this query ready, convert it into an INSERT into the temporary table TEMPO_T along with whatever values you need to store for columns D_3 and D_4.
Now, you have a backup of the original contents of column C_T and hence can delete the column.
Now, you can update the type that defines the structure of column C_T to its new form (i.e. D_1,...,D_5) and alter table T1 by adding a column whose type is the updated one.
Finally, you can insert the contents of column C_T with that stored in the temporary table (since you already have this, I assume that you know how to implement it - inserting a table within a cell column of the outer table).
That's it.
Needless to say, I would make a backup of your data before engaging into this.
Hope this description is detailed enough to enable you to complete the task at hand.
I have two tables (master-detail) I use to record orders, I need to create a trigger that allows me to update the "TOTAL_GENERAL" field that is in the master table with the sum of subtotals in the "SUBTOTAL" field the detail table that are related to the foreign key "ID_ORDEN" but I get an error with the trigger.
tables:
CREATE TABLE "ENCABEZADO_ORDEN"
("ID_ENCABEZADO" NUMBER(10,0),
"NUMERO_ORDEN" NUMBER(10,0),
"FECHA" DATE,
"NOMBRE_CLIENTE" VARCHAR2(50),
"DIRECCION" VARCHAR2(50),
"TOTAL_GENERAL" NUMBER(10,0),
"LUGAR_VENTA" VARCHAR2(50),
CONSTRAINT "ENCABEZADO_ORDEN_PK" PRIMARY KEY ("ID_ENCABEZADO")
USING INDEX ENABLE
)
CREATE TABLE "DETALLE_ORDEN"
("ID_DETALLE" NUMBER(10,0),
"PRODUCTO" VARCHAR2(50),
"PRECIO_UNITARIO" NUMBER(10,2),
"CANTIDAD" NUMBER(10,0),
"SUBTOTAL" NUMBER(10,2),
"ID_ENCABEZADO" NUMBER(10,0),
CONSTRAINT "DETALLE_ORDEN_PK" PRIMARY KEY ("ID_DETALLE")
USING INDEX ENABLE
)
/
ALTER TABLE "DETALLE_ORDEN" ADD CONSTRAINT "DETALLE_ORDEN_FK" FOREIGN KEY ("ID_ENCABEZADO")
REFERENCES "ENCABEZADO_ORDEN" ("ID_ENCABEZADO") ENABLE
/
trigger:
create or replace TRIGGER "CALCULAR_TOTAL_GENERAL"
BEFORE INSERT OR UPDATE ON "DETALLE_ORDEN"
FOR EACH ROW
DECLARE
V_ID_ENCABEZADO NUMBER(10,0);
BEGIN
SELECT "ID_ENCABEZADO"
INTO V_ID_ENCABEZADO
FROM "ENCABEZADO_ORDEN"
WHERE "ID_ENCABEZADO" = :NEW."ID_ENCABEZADO";
UPDATE "ENCABEZADO_ORDEN"
SET "TOTAL_GENERAL" = (SELECT SUM("SUBTOTAL") FROM "DETALLE_ORDEN"
WHERE "ID_ENCABEZADO" = V_ID_ENCABEZADO)
WHERE "ID_ENCABEZADO" = V_ID_ENCABEZADO;
END;
This is the error message I get when I insert or update the table "DETALLE_ORDEN":
1 error has occurred
ORA-04091: table CARLOSM.DETALLE_ORDEN is mutating, trigger/function may not see it
ORA-06512: at "CARLOSM.CALCULAR_TOTAL_GENERAL", line 9
ORA-04088: error during execution of trigger 'CARLOSM.CALCULAR_TOTAL_GENERAL'
Don't use triggers for this kind of logic (for that matter, don't use triggers ever; there's almost always a better way). Also, avoid storing redundant information in base tables whenever possible.
Far better design, with minimal impact to existing code is to
1) rename table "ENCABEZADO_ORDEN" (i.e. to "ENCABEZADO_ORDEN_TAB") and 2) disable/drop "TOTAL_GENERAL" field, and then 3) create a view with original name "ENCABEZADO_ORDEN" as:
CREATE OR REPLACE VIEW ENCABEZADO_ORDEN AS
SELECT O.*, (SELECT SUM(D.SUBTOTAL) FROM DETALLE_ORDEN D
WHERE D.ID_ENCABEZADO = O.ID_ENCABEZADO) TOTAL_GENERAL
FROM ENCABEZADO_ORDEN_TAB O;
This will ensure TOTAL_GENERAL is always correct (in fact, any efforts to set it directly to some other value via update of ENCABEZADO_ORDEN will result in immediate syntax error).
If performance is an issue (i.e. users frequently query TOTAL_GENERAL field in ENCABEZADO_ORDEN table for orders with large numbers of detail records in DETALLE_ORDEN, causing Oracle to repeatedly fetch&sum multitudes of SUBTOTALS) then use a materialized view instead of a basic view.
I'm recieving the ORA-01403 no data found error when trying to insert in a table after creating the following trigger:
CREATE OR REPLACE TRIGGER unic_disc
BEFORE insert ON disciplina
FOR EACH ROW
DECLARE
CURSOR cursor_professor IS
SELECT matricula_professor
FROM disciplina;
temp_prof disciplina.matricula_professor%type;
BEGIN
OPEN cursor_professor;
FETCH cursor_professor INTO temp_prof;
CLOSE cursor_professor;
END;
/
(the variables are in portugues, but their name does not interfere in the logic.)
the table creation,
CREATE TABLE disciplina (
codigo_disciplina NUMBER,
ementa VARCHAR2(50) NOT NULL,
conteudo_programatico VARCHAR2(100) NOT NULL,
matricula_professor NUMBER NOT NULL,
CONSTRAINT disciplina_pk PRIMARY KEY (codigo_disciplina),
CONSTRAINT disciplina_matricula_prof_fk FOREIGN KEY (matricula_professor) REFERENCES professor (matricula_professor)
);
My insert query:
INSERT INTO disciplina (codigo_disciplina,ementa,conteudo_programatico,matricula_professor) VALUES (7,'E6', 'C6',7777);
EDIT: I think the error is because I am selecting from the same table I'm editing.
I just needed to add PRAGMA_AUTONOMOUS_TRANSACTION after the DECLARE AND IT WORKED. I couldn't find it on my own, a friend told me.
Yes you are using a trigger (before insert) initially the table does not have any data and
the trigger is fired before insert when you are trying to insert data in the table, it
returns you with no records found . if you specify what is your requirement exactly i will
try to help you with the code .
I am trying to create a trigger which will enter values into a table terminated_employees when we delete values from the nm_employees table. I have written the trigger but it does not work. Is my trigger format right? Any ideas?
CREATE TABLE nm_departments(
dept2 varchar(20),
CONSTRAINT empPK PRIMARY KEY (dept2)
);
CREATE TABLE nm_employees(
name varchar(20),
dept varchar(20),
CONSTRAINT departments FOREIGN KEY (dept) REFERENCES nm_departments (dept2)ON DELETE CASCADE
);
CREATE TABLE terminated_employees(
te_name varchar(20),
te_dept varchar(20)
);
CREATE TRIGGER term_employee AFTER DELETE ON nm_employee
FOR EACH ROW
BEGIN
INSERT INTO terminated_employees (NEW.te_name, NEW.te_dept) VALUES (OLD.name,OLD.dept)
END;
You should not be specifying the NEW. on the column names of your INSERT statement. These are the columns in the terminated_employees table, NOT the new values. i.e.
INSERT INTO terminated_employees (te_name, te_dept)
VALUES (OLD.name,OLD.dept)
You can use show errors (or show err) in SQL*Plus to see the exact error.
You have a number of problems:
Wrong table name on create trigger (missing the s)
Missing ; after instert statement
The OLD. need to have : prefix. i.e. :OLD.name
I create a table in Oracle 11g with the default value for one of the columns. Syntax is:
create table xyz(emp number,ename varchar2(100),salary number default 0);
This created successfully. For some reasons I need to create another table with same old table structure and data. So I created a new table with name abc as
create table abc as select * from xyz.
Here "abc" created successfully with same structure and data as old table xyz. But for the column "salary" in old table "xyz" default value was set to "0". But in the newly created table "abc" the default value is not set.
This is all in Oracle 11g. Please tell me the reason why the default value was not set and how we can set this using select statement.
You can specify the constraints and defaults in a CREATE TABLE AS SELECT, but the syntax is as follows
create table t1 (id number default 1 not null);
insert into t1 (id) values (2);
create table t2 (id default 1 not null)
as select * from t1;
That is, it won't inherit the constraints from the source table/select. Only the data type (length/precision/scale) is determined by the select.
The reason is that CTAS (Create table as select) does not copy any metadata from the source to the target table, namely
no primary key
no foreign keys
no grants
no indexes
...
To achieve what you want, I'd either
use dbms_metadata.get_ddl to get the complete table structure, replace the table name with the new name, execute this statement, and do an INSERT afterward to copy the data
or keep using CTAS, extract the not null constraints for the source table from user_constraints and add them to the target table afterwards
You will need to alter table abc modify (salary default 0);
new table inherits only "not null" constraint and no other constraint.
Thus you can alter the table after creating it with "create table as" command
or you can define all constraint that you need by following the
create table t1 (id number default 1 not null);
insert into t1 (id) values (2);
create table t2 as select * from t1;
This will create table t2 with not null constraint.
But for some other constraint except "not null" you should use the following syntax
create table t1 (id number default 1 unique);
insert into t1 (id) values (2);
create table t2 (id default 1 unique)
as select * from t1;