dump_sql: Show generated sql

In dcmodifydb: Modifying Rules on a DataBase

Show generated sql

Description

Writes the generated sql to a file or command line. The script contains ALTER and UPDATE statements and can be used for documentation purposes.

Usage

dump_sql(x, table, con = NULL, file = stdout(), ...)

Arguments

x	dcmodify::modifier() object with rules to be written
table	either a dplyr::tbl() object or a character with table name
con	optional, when table is a character, a dbi connection.
file	to which the sql will be written.
...	not used

Details

Note that when this script is run on the database it will change the original table. This differs from the default behavior of dcmodify which works on a (temporary) copy of the table.

Furthermore, it seems wise to wrap the generated SQL in a transaction when apply the SQL code on a database.

Value

character sql script with all statements.

See Also

Other sql translation: modifier_to_sql()

Examples

# load modification rules and apply:
library(dcmodify)

con <- DBI::dbConnect(RSQLite::SQLite(), dbname=system.file("db/person.db", package="dcmodifydb"))
person <- dplyr::tbl(con, "person")

rules <- modifier(.file = system.file("db/corrections.yml", package="dcmodifydb"))
print(rules)

# show sql code generated from the rules.
dump_sql(rules, person)

dcmodifydb documentation built on June 17, 2022, 5:05 p.m.