There a concept cursor in python to manipulate database,such as:
cu = cx.cursor()
cu.execute('create table catalog (id integer primary key,pid integer,name varchar(10) UNIQUE）')
Is there a same kind of way to manipulate database in R?
take a look at the package sqldf .
It has an excellent documentation here : https://code.google.com/p/sqldf/
library(sqldf)
# create new empty database called mydb
sqldf("attach 'mydb' as new")
sqldf("create table catalog (id integer not null, pid integer,name text(10) ）", dbname = "mydb")
#close
sqldf()
P.S: Perhaps you should explain a little bit what you want to do. If you are already "connected" to a database, then specify which engine (because of different SQL statements in creating tables etc ....)
Related
There is this script in the SQL Server that needs to be converted in PostgreSQL.
Here is the script:
UPDATE Categories_convert SET Categories_convert.ParentID =
Categories_convert_1.CategoryID
FROM Categories_convert LEFT OUTER JOIN Categories_convert AS
Categories_convert_1 ON Categories_convert.MainGroupID_FK =
Categories_convert_1.MainGroupID
WHERE (((Categories_convert.Level)=2));
Then I tried to convert it to postgres. Here is the script:
UPDATE x_tmp_categories_convert SET orig.parentid =
cat2.categoryid
FROM x_tmp_categories_convert LEFT OUTER JOIN x_tmp_categories_convert AS
cat2 ON x_tmp_categories_convert.maingroupid_fk =
x_tmp_categories_convert.maingroupid
WHERE (((cat.level)=2));
Note that I have already created the table Categories_convert of SQLServer to Postgresql and renamed it to x_tmp_categories_convert .
All the fields in postgresql is in lowercase.
Now the problem is when i execute the converted script to postgresql, an error will occur:
ERROR: table name "x_tmp_categories_convert" specified more than once
SQL state: 42712
What I do wrong in the conversion?
UPDATE:
I have tried #a_horse_with_no_name 's answer but it didn't update the records at all. The parentid field is still empty. It is supposed to map all the parentid of that categor based on its maingoupid_fk.
Below is a snapshot of the records after executing the suggested script.
I have opted out the name for disclosure reasons.
Records snapshot link
UPDATE v2:
I am using php to migrate the data so pardon me for the variables used.
Here are the 2 insert statements used before the questioned update script is executed:
INSERT INTO x_tmp_categories_convert(maingroupid,name,vendorid,level,parentid)
VALUES ($id,'$mainGroup',$vendorID,1,Null);
INSERT INTO x_tmp_categories_convert(subgroupid,maingroupid_fk,name,vendorid,level)
VALUES ($id,'$mainGroupId','$subGroup',$vendorID,2);
Also, this is the table definition of the x_tmp_categories_convert table:
CREATE TABLE x_tmp_categories_convert
(
categoryid serial NOT NULL,
parentid double precision,
name character varying(255),
level double precision,
vendorid double precision,
maingroupid integer,
subgroupid integer,
maingroupid_fk integer,
pageid integer,
subgroupid_fk integer,
CONSTRAINT code_pk PRIMARY KEY (categoryid)
)
WITH (
OIDS=FALSE
);
UPDATE v3:
Already SOLVED by a_horse_with_no_name. Thank you
I have edited #a_horse_with_no_name 's answer and to make it work. I guess it is just a copy paste error.
Here is the final script:
UPDATE x_tmp_categories_convert
SET parentid = cat.categoryid
FROM x_tmp_categories_convert AS cat
WHERE x_tmp_categories_convert.maingroupid_fk = cat.maingroupid
AND x_tmp_categories_convert.level = 2;
For #a_horse_with_no_name, I am very grateful to you as I cannot come up with the solution without your help. +1 for you man. Thank you
I have a small database that I'm developing SQL Server 2008.
I don't have much SQL experience overall, so finding it difficult to find information as to what the appropriate pattern for this issue is.
The main table is 'Provider' a Provider can be a 'MatchService', a 'CompareService', or both depending on 'ProviderTypeId'. I'm looking to contrain data in the MatchService and CompareService tables based on the following rules:
1) A Provider with a ProviderTypeId = Lender can be both a MatchService and a CompareService;
2) A Provider with a ProviderTypeId = Pingtree can only be a MatchService.
I know that a solution probably includes a bridge table in the schema but I'm unsure as to what and where. Any advice appreciated.
Maby something like this:
CREATE TRIGGER MatchService_ITrig
ON MatchService
FOR INSERT
AS
IF NOT EXISTS (
SELECT
ProviderID
FROM
Provider p
INNER JOIN
inserted i ON
P.ID = I.ProviderID
WHERE
ProviderTypeID = 'Lender' OR
ProviderTypeID = 'PingTree'
)
BEGIN
ROLLBACK TRANSACTION
END
How about :
ALTER TABLE CompareService
ADD CONSTRAINT chkPTID CHECK (ProviderTypeId = Lender);
GO
Raj
I can't solve my problem with my local Oracle database.
I'm tryong to connect to my local Oracle database (Oracle Database 11g Express Edition)
Later on I will use JNDI to another Oracle Database, but I think this should still work.
Driver: ojdbc6.jar in /lib
db.default.driver=oracle.jdbc.driver.OracleDriver
db.default.url="jdbc:oracle:thin:#localhost:1521:xe"
db.default.user="user"
db.default.pass="pass"
So I know I do connect to the database, but the error is that it says that the table does not exist. I'm not even creating or querying to a table (no model exists - but I've tried with having a model too, same error). Something seems to be wrong in the beginning and I don't know how to Debug this.
Error:
**java.sql.SQLSyntaxErrorException: ORA-00942: table or view does not exist**
oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:457)
oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:400)
oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:926)
oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:476)
oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:200)
oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:543)
oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:197)
oracle.jdbc.driver.T4CStatement.executeForDescribe(T4CStatement.java:1213)
oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1492)
oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1710)
oracle.jdbc.driver.OracleStatement.executeQuery(OracleStatement.java:2006)
oracle.jdbc.driver.OracleStatementWrapper.executeQuery(OracleStatementWrapper.java:1709)
com.jolbox.bonecp.StatementHandle.executeQuery(StatementHandle.java:503)
play.api.db.evolutions.Evolutions$.executeQuery(Evolutions.scala:118)
play.api.db.evolutions.Evolutions$.databaseEvolutions(Evolutions.scala:334)
play.api.db.evolutions.Evolutions$.evolutionScript(Evolutions.scala:306)
play.api.db.evolutions.EvolutionsPlugin$$anonfun$onStart$1$$anonfun$apply$1.apply$mcV$sp(Evolutions.scala:435)
play.api.db.evolutions.EvolutionsPlugin.withLock(Evolutions.scala:478)
play.api.db.evolutions.EvolutionsPlugin$$anonfun$onStart$1.apply(Evolutions.scala:434)
play.api.db.evolutions.EvolutionsPlugin$$anonfun$onStart$1.apply(Evolutions.scala:432)
scala.collection.immutable.List.foreach(List.scala:309)
play.api.db.evolutions.EvolutionsPlugin.onStart(Evolutions.scala:432)
play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:63)
play.api.Play$$anonfun$start$1$$anonfun$apply$mcV$sp$1.apply(Play.scala:63)
scala.collection.immutable.List.foreach(List.scala:309)
play.api.Play$$anonfun$start$1.apply$mcV$sp(Play.scala:63)
play.api.Play$$anonfun$start$1.apply(Play.scala:63)
play.api.Play$$anonfun$start$1.apply(Play.scala:63)
When reading about it I've only found that I might not have permission to some table, but the thing is that I use the same login in Oracle SQL Developer and it works.
As nico_ekito wrote, you need to create this table manually.
This one works for me:
CREATE TABLE play_evolutions
(
id Number(10,0) Not Null Enable,
hash VARCHAR2(255 Byte),
applied_at Timestamp Not Null,
apply_script clob,
revert_script clob,
state Varchar2(255),
last_problem clob,
CONSTRAINT play_evolutions_pk PRIMARY KEY (id)
);
Try to manually create a play_evolutions table with the following columns (by adapting the types to the ones used by Oracle):
id int not null primary key, hash varchar(255) not null,
applied_at timestamp not null,
apply_script text,
revert_script text,
state varchar(255),
last_problem text
In conf/application.conf
Un-comment the following line:
evolutionplugin=disabled
This is if you don't need Evolutions (to track schema changes).
I want to create VIEW definitions on MS Access. I have used following CREATE VIEW Statement:
SELECT
MFP.FollowUpPlan_Id,
MFP.FollowUpPlan_Name AS PlanName,
DFP.Sequence_No AS SequenceNo,
MFS.FollowUpSchedule_Name AS ScheduleName
FROM
MAS_FollowUp_Plan AS MFP,
DET_FollowUp_Plan AS DFP,
MAS_FollowUp_Schedule AS MFS
WHERE
(((MFP.FollowUpPlan_Id)=DFP.FollowUpPlan_Id) AND
((DFP.FollowUpSchedule_Id)=MFS.FollowUpSchedule_Id)) AND
MFP.is_Deleted = FALSE AND
DFP.is_Deleted = false
ORDER BY
MFP.FollowUpPlan_Id, DFP.Sequence_No;
but it throw an error:
Only Simple Select Queries are allowed in view.
Please Help, Thanks in Advance.
The issue here, as Jeroen explained, is a limitation of Access' CREATE VIEW statement. For this case, you can use CREATE PROCEDURE instead. It will create a new member of the db's QueryDefs collection --- so from the Access user interface will appear as a new named query.
The following statement worked for me using ADO from VBScript. From previous Delphi questions on here, my understanding is that Delphi can also use ADO, so I believe this should work for you, too.
CREATE PROCEDURE ViewSubstitute AS
SELECT
MFP.FollowUpPlan_Id,
MFP.FollowUpPlan_Name AS PlanName,
DFP.Sequence_No AS SequenceNo,
MFS.FollowUpSchedule_Name AS ScheduleName
FROM
(MAS_FollowUp_Plan AS MFP
INNER JOIN DET_FollowUp_Plan AS DFP
ON MFP.FollowUpPlan_Id = DFP.FollowUpPlan_Id)
INNER JOIN MAS_FollowUp_Schedule AS MFS
ON DFP.FollowUpSchedule_Id = MFS.FollowUpSchedule_Id
WHERE
MFP.is_Deleted=False AND DFP.is_Deleted=False
ORDER BY
MFP.FollowUpPlan_Id,
DFP.Sequence_No;
You cannot mix ORDER BY with JOIN when creating views in Access. It will get you the error "Only simple SELECT queries are allowed in VIEWS." (note the plural VIEWS)
Having multiple tables in the FROM is a kind of to JOIN.
either remove the ORDER BY,
or have only one table in the FROM and no JOINs.
I remember from the past (when I did more Access stuff than now) seeing this for a large query with a single table select with an ORDER BY as well.
The consensus is that you should not have ORDER BY in views anyway, so that is your best thing to do.
Another reason that you can get the same error message is if you add parameters or sub selects. Access does not like those in views either, but that is not the case in your view.
Declare variable olevarCatalog ,cmd as OleVariant in Delphi, Uses ComObj
olevarCatalog := CreateOleObject('ADOX.Catalog');
olevarCatalog.create(YourConnectionString); //This Will create MDB file.
// Using ADO Query(CREATE TABLE TABLEName....) add the required Tables.
// To Insert View Definition on MDB file.
cmd := CreateOleObject('ADODB.Command');
cmd.CommandType := cmdText;
cmd.CommandText := 'ANY Kind of SELECT Query(JOIN, OrderBy is also allowed)';
olevarCatalog.Views.Append('Name of View',cmd);
cmd := null;
This is a best way to Create MS ACCESS File(.MDB) and VIEWs using Delphi.
I have 2 SQLite databases with common data but with different purposes and I wanted to avoid reinserting data, so I was wondering if it was possible to copy a whole table from one database to another?
You'll have to attach Database X with Database Y using the ATTACH command, then run the appropriate Insert Into commands for the tables you want to transfer.
INSERT INTO X.TABLE SELECT * FROM Y.TABLE;
// "INSERT or IGNORE" if you want to ignore duplicates with same unique constraint
Or, if the columns are not matched up in order:
INSERT INTO X.TABLE(fieldname1, fieldname2) SELECT fieldname1, fieldname2 FROM Y.TABLE;
Easiest and correct way on a single line:
sqlite3 old.db ".dump mytable" | sqlite3 new.db
The primary key and the columns types will be kept.
Consider a example where I have two databases namely allmsa.db and atlanta.db. Say the database allmsa.db has tables for all msas in US and database atlanta.db is empty.
Our target is to copy the table atlanta from allmsa.db to atlanta.db.
Steps
sqlite3 atlanta.db(to go into atlanta database)
Attach allmsa.db. This can be done using the command ATTACH '/mnt/fastaccessDS/core/csv/allmsa.db' AS AM;
note that we give the entire path of the database to be attached.
check the database list using sqlite> .databases
you can see the output as
seq name file
--- --------------- ----------------------------------------------------------
0 main /mnt/fastaccessDS/core/csv/atlanta.db
2 AM /mnt/fastaccessDS/core/csv/allmsa.db
now you come to your actual target. Use the command
INSERT INTO atlanta SELECT * FROM AM.atlanta;
This should serve your purpose.
For one time action, you can use .dump and .read.
Dump the table my_table from old_db.sqlite
c:\sqlite>sqlite3.exe old_db.sqlite
sqlite> .output mytable_dump.sql
sqlite> .dump my_table
sqlite> .quit
Read the dump into the new_db.sqlite assuming the table there does not exist
c:\sqlite>sqlite3.exe new_db.sqlite
sqlite> .read mytable_dump.sql
Now you have cloned your table.
To do this for whole database, simply leave out the table name in the .dump command.
Bonus: The databases can have different encodings.
Objective-C code for copy Table from a Database to another Database
-(void) createCopyDatabase{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
NSString *maindbPath = [documentsDir stringByAppendingPathComponent:#"User.sqlite"];;
NSString *newdbPath = [documentsDir stringByAppendingPathComponent:#"User_copy.sqlite"];
NSFileManager *fileManager = [NSFileManager defaultManager];
char *error;
if ([fileManager fileExistsAtPath:newdbPath]) {
[fileManager removeItemAtPath:newdbPath error:nil];
}
sqlite3 *database;
//open database
if (sqlite3_open([newdbPath UTF8String], &database)!=SQLITE_OK) {
NSLog(#"Error to open database");
}
NSString *attachQuery = [NSString stringWithFormat:#"ATTACH DATABASE \"%#\" AS aDB",maindbPath];
sqlite3_exec(database, [attachQuery UTF8String], NULL, NULL, &error);
if (error) {
NSLog(#"Error to Attach = %s",error);
}
//Query for copy Table
NSString *sqlString = #"CREATE TABLE Info AS SELECT * FROM aDB.Info";
sqlite3_exec(database, [sqlString UTF8String], NULL, NULL, &error);
if (error) {
NSLog(#"Error to copy database = %s",error);
}
//Query for copy Table with Where Clause
sqlString = #"CREATE TABLE comments AS SELECT * FROM aDB.comments Where user_name = 'XYZ'";
sqlite3_exec(database, [sqlString UTF8String], NULL, NULL, &error);
if (error) {
NSLog(#"Error to copy database = %s",error);
}
}
The Easiest way to do is through SQLite Studio
If you don't have download from https://download.cnet.com/SQLiteStudio/3000-10254_4-75836135.html
Steps:
1.Add both the databases.
2.Click View tab and then databases as shown in the picture.
3.Right click the table you want to copy and copy it.
Paste the table after right clicking the database where you want to paste.
Now you're done
First scenario: DB1.sqlite and DB2.sqlite have the same table(t1), but DB1 is more "up to date" than DB2. If it's small, drop the table from DB2 and recreate it with the data:
> DROP TABLE IF EXISTS db2.t1; CREATE TABLE db2.t1 AS SELECT * FROM db1.t1;
Second scenario: If it's a large table, you may be better off with an INSERT if not exists type solution. If you have a Unique Key column it's more straight forward, otherwise you'd need to use a combination of fields (maybe every field) and at some point it's still faster to just drop and re-create the table; it's always more straight forward (less thinking required).
THE SETUP: open SQLite without a DB which creates a temporary in memory main database, then attach DB1.sqlite and DB2.sqlite
> sqlite3
sqlite> ATTACH "DB1.sqlite" AS db1
sqlite> ATTACH "DB2.sqlite" AS db2
and use .databases to see the attached databases and their files.
sqlite> .databases
main:
db1: /db/DB1.sqlite
db2: /db/DB2.sqlite
I needed to move data from a sql server compact database to sqlite, so using sql server 2008 you can right click on the table and select 'Script Table To' and then 'Data to Inserts'. Copy the insert statements remove the 'GO' statements and it executed successfully when applied to the sqlite database using the 'DB Browser for Sqlite' app.
If you use DB Browser for SQLite, you can copy the table from one db to another in following steps:
Open two instances of the app and load the source db and target db side by side.
If the target db does not have the table, "Copy Create Statement" from the source db and then paste the sql statement in "Execute SQL" tab and run the sql to create the table.
In the source db, export the table as a CSV file.
In the target db, import the CSV file to the table with the same table name. The app will ask you do you want to import the data to the existing table, click yes. Done.