I'm trying to create a table containing opening hours (for cafeteria's)
However I am having some issues with implementing the constraint. For each resto, the openinghours cannot overlap.
CREATE table openinghours(
id serial PRIMARY key,
start timestamp NOT NULL,
duration interval NOT NULL,
resto_naam varchar REFERENCES resto(naam),
constraint openingstijden_duplicate_check EXCLUDE USING GIST (
resto_naam WITH =,
/* Check wether there is no overlap between the dates */
tsrange(start, start + duration) WITH &&
)
);
when I try to execute this SQL I get the following error:
ERROR: data type character varying has no default operator class for access method "gist"
HINT: You must specify an operator class for the index or define a default operator class for the data type.
SQL state: 42704
Any help would be appreciated!
You need the btree_gist extension for this to work. Execute create btree_gist and try again.
Best regards,
Bjarni
Related
For a test tomorrow we're told to name our constraints
I know it's possible to create a constraint when you use ALTER TABLE
but can you add a name to a not null constraint when you CREATE TABLE?
f.e.
CREATE TABLE test (
test1 VARCHAR
CONSTRAINT nn_test1 NOT NULL (test1)
)
I get an error when trying to run this query. Am I writing it wrong?
The error I get is
ERROR: syntax error at or near "NOT"
LINE 3: CONSTRAINT nn_test1 NOT NULL (test1))
^
SQL state: 42601
Character: 56
You have two options to define a named not null constraint:
Inline with the column:
CREATE TABLE test
(
test1 VARCHAR CONSTRAINT nn_test1 NOT NULL,
test2 integer --<< no comma because it's the last column
);
Or at the end of columns as an out-of-line constraint. But then you need a check constraint:
CREATE TABLE test
(
test1 VARCHAR,
test2 integer, --<< comma required after the last column
constraint nn_test1 check (test1 is not null)
);
This has become irrelevant, since you're not using SQL Server
First of all, you should always specify a length for a VARCHAR. Not doing so (in SQL Server variables, or parameters) may result in a string of just exactly ONE character in length - typically NOT what you want.
Then, you need to just specify the NOT NULL - there's no need to repeat the column name (actually this is the error) - if you're specifying the CONSTRAINT "inline" with the column definition (which is a perfectly legal and in my opinion the preferred way of doing this).
Try this code:
CREATE TABLE test
(
test1 VARCHAR(50)
CONSTRAINT nn_test1 NOT NULL
)
At least this is the CREATE TABLE statement that works in T-SQL / SQL Server - not sure about PostgreSQL (don't know it well enough, don't have it at hand to test right now).
I, a_horse_with_no_name, the two syntax:
constraint nn_test1 check (test1 is not null)
and
test1 VARCHAR CONSTRAINT nn_test1 NOT NULL
are equivalent ? performance correctly ecc.
Because in first case the SQL server exception return the name nn_test so the system know exactly error.
I have the following table:
create table booking (
identifier integer not null primary key,
room uuid not null,
start_time time without time zone not null,
end_time time without time zone not null
);
I want to create an exclude constraint to enforce that there are no overlapping appointments for the same room.
I tried the following:
alter table booking add constraint overlapping_times
exclude using gist
(
cast(room as text) with =,
period(start_time, end_time) with &&)
);
This has two problems:
Casting room to text is not enough, it gives: ERROR: data type text has no default operator class for access method "gist". I know in v10 there is btree_gist, but I am using v9.5 and v9.6, so I have to manually cast the uuid to a text afaik.
period(...) is wrong, but I have no idea how to construct a range of time without time zone type.
After installing btree_gist, you can do the following:
create type timerange as range (subtype = time);
alter table booking add constraint overlapping_times
exclude using gist
(
(room::text) with =,
timerange(start_time, end_time) with &&
);
If you want an expression in the constraint you need to put that into parentheses. So either (room::text) or (cast(room as text))
I am trying to create a table in Oracle SQL Developer but I am getting error ORA-00902.
Here is my schema for the table creation
CREATE TABLE APPOINTMENT(
Appointment NUMBER(8) NOT NULL,
PatientID NUMBER(8) NOT NULL,
DateOfVisit DATE NOT NULL,
PhysioName VARCHAR2(50) NOT NULL,
MassageOffered BOOLEAN NOT NULL, <-- the line giving the error -->
CONSTRAINT APPOINTMENT_PK PRIMARY KEY (Appointment)
);
What am I doing wrong?
Thanks in advance
Last I heard there were no boolean type in oracle. Use number(1) instead!
Oracle does not support the boolean data type at schema level, though it is supported in PL/SQL blocks. By schema level, I mean you cannot create table columns with type as boolean, nor nested table types of records with one of the columns as boolean. You have that freedom in PL/SQL though, where you can create a record type collection with a boolean column.
As a workaround I would suggest use CHAR(1 byte) type, as it will take just one byte to store your value, as opposed to two bytes for NUMBER format. Read more about data types and sizes here on Oracle Docs.
Oracle doesn't support boolean for table column datatype. You should probably use a CHAR(1) (Y/N)
You can see more info on this other answer
i think u got a below good result
http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/datatypes.htm#CJACJGBG
When using an Entity class to create the schema, defining the boolean value as below will help
#Column(columnDefinition = "number default 0")
private boolean picked;
Postgresql 9.2 reservation table contains objekt2 column whose type is char(10).
The following code is used to create non-overlapped reservations table:
CREATE TABLE reservat (
id serial primary key,
objekt2 char(10) references yksus2,
during tsrange,
rida int references rid on delete cascade not null,
EXCLUDE USING gist (objekt2 text_pattern_ops WITH =, during WITH &&)
);
This causes error:
ERROR: operator class "text_pattern_ops" does not exist for access
method "gist"
How to fix this error so that char(10) type columns can used for reservations and overlapping reservations are not allowed for same objekt2 values ?
You need to use btree_gist extension. There is an example in the docs about this: Constraints on Ranges
I have set-up a table using the following SQL script:
CREATE TABLE MY_TABLE (
ID NUMBER NOT NULL,
CODE VARCHAR2(40) NOT NULL,
CONSTRAINT MY_TABLE PRIMARY KEY (ID)
);
CREATE UNIQUE INDEX XUNIQUE_MY_TABLE_CODE ON MY_TABLE (CODE);
The problem is that I need to ensure that CODE does not have a leading zero for its value.
How do I accomplish this in SQL so that a 40-char value without a leading zero is stored?
CODE VARCHAR2 NOT NULL CHECK (VALUE not like '0%')
sorry - slight misread on the original spec
If you can guarantee that all INSERTs and UPDATEs to this table are done through a stored procedure, you could put some code there to check that the data is valid and return an error if not.
P.S. A CHECK CONSTRAINT would be better, except that MySQL doesn't support them.