
db.obj
object or a table/view in the databaseThis function deletes a db.data.frame
object together with the
table/view that it points to. It deletes a db.Rquery
object. It
can also directly delete a table or view in the database. When applied
onto some composite data objects, it deletes the data table wrapped by
them.
# S4 method for db.data.frame
delete(x, cascade = FALSE)# S4 method for db.Rquery
delete(x)
# S4 method for character
delete(x, conn.id = 1, is.temp = FALSE, cascade =
FALSE)
# S4 method for arima.css.madlib
delete(x)
# S4 method for summary.madlib
delete(x)
# S4 method for lm.madlib
delete(x)
# S4 method for lm.madlib.grps
delete(x)
# S4 method for logregr.madlib
delete(x)
# S4 method for logregr.madlib.grps
delete(x)
# S4 method for bagging.model
delete(x)
# S4 method for elnet.madlib
delete(x)
# S4 method for dt.madlib
delete(x)
# S4 method for dt.madlib.grps
delete(x)
The signature of the method.
A db.data.frame
object, which
points to a table or view in the database;
Or a db.Rquery
object, which represents some operations on an existing
db.data.frame
object;
Or a string, the table/view name to delete in the database;
Or an object which is the result of madlib.arima
. In the
this case, the result model tables wrapped by model
,
residuals
and statistics
will be deleted.
Or an object which is the result of madlib.summary
(a
summary.madlib
object). In this case the result table created
in the database and wrapped by the attribute
"summary"
will be deleted.
Or an object which is the result of madlib.lm
(a
lm.madlib
or lm.madlib.grps
object). In this
case, the result model table wrapped by model
will be
deleted.
Or an object which is the result of madlib.glm
with
family = "binomial"
(a
logregr.madlib
or logregr.madlib.grps
object). In this
case, the result model table wrapped by model
will be
deleted.
Or an object which is the result of generic.bagging
. In this case, all result model tables will be deleted.
Or an object which is the result of madlib.elnet
. In this casem all result model tables will be deleted.
Or an object which is the result of madlib.rpart
. All result
tables will be deleted.
An integer, default is 1. The connection ID to the database.
A logical, default is FALSE
. Whether the table/view is temporary.
A logical, default is FALSE
. Whether to delete objects together
with all the objects depending on it.
When x
is db.data.frame
or table/view name, this
function returns a logical value. which is TRUE
if the deletion
is successful.
No value is returned if x
is db.Rquery
When a db.data.frame
object is deleted, the table/view that is
associated with it is also deleted.
db.data.frame
creates an object pointing to a table/view
in the database.
db.objects
lists all tables and views in a database
together with their schema.
db.existsObject
tests whether a table/view exists in the
database.
as.db.data.frame
creates a db.data.frame
from a
data.frame
, a data file or a db.Rquery
.
madlib.lm
, madlib.glm
,
madlib.summary
, madlib.arima
are MADlib
wrapper functions whose results can be safely deleted by this function.
# NOT RUN {
<!-- %% @test .port Database port number -->
<!-- %% @test .dbname Database name -->
## set up the database connection
## Assume that .port is port number and .dbname is the database name
cid <- db.connect(port = .port, dbname = .dbname, verbose = FALSE)
delete("abalone", cid, is.temp = TRUE)
delete("abalone", cid, is.temp = FALSE)
delete("abalone", conn.id = cid)
x <- as.db.data.frame(abalone, "abalone", conn.id = cid)
lk(x, 10)
y <- as.db.data.frame(abalone, "abalone", conn.id = cid, is.temp = TRUE)
lk(y, 10)
db.existsObject("abalone", cid, is.temp = TRUE)
db.existsObject("abalone", cid, is.temp = FALSE)
delete("abalone", cid)
p <- db.objects()
p[p == "abalone"]
## Example: delete multiple tables
## all table in public schema start with "ornste"
to.delete <- db.objects("public.ornste", conn.id = cid)
for (table.name in to.delete) delete(table.name, conn.id = cid)
db.disconnect(cid, verbose = FALSE)
# }
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