Add or remove a column to/from a table.
Usage
dbColumn(
conn,
name,
colname,
action = c("add", "drop"),
coltype = "integer",
cascade = FALSE,
display = TRUE,
exec = TRUE
)
Arguments
- conn
A connection object.
- name
A character string specifying a PostgreSQL table name.
- colname
A character string specifying the name of the column
- action
A character string specifying if the column is to be added (
"add"
, default) or removed ("drop"
).- coltype
A character string indicating the type of the column, if
action = "add"
.- cascade
Logical. Whether to drop foreign key constraints of other tables, if
action = "drop"
.- display
Logical. Whether to display the query (defaults to
TRUE
).- exec
Logical. Whether to execute the query (defaults to
TRUE
).
See also
The PostgreSQL documentation: http://www.postgresql.org/docs/current/static/sql-altertable.html
Author
Mathieu Basille mathieu@basille.org
Examples
## examples use a dummy connection from DBI package
conn<-DBI::ANSI()
## Add an integer column
dbColumn(conn, name = c("schema", "table"), colname = "field", exec = FALSE)
#> Query not executed:
#> ALTER TABLE "schema"."table" ADD COLUMN "field" integer;
## Drop a column (with CASCADE)
dbColumn(conn, name = c("schema", "table"), colname = "field", action = "drop",
cascade = TRUE, exec = FALSE)
#> Query not executed:
#> ALTER TABLE "schema"."table" DROP COLUMN "field" CASCADE;