Generate SQL from R expressions
Low-level building block for generating SQL from R expressions.
Strings are escaped; names become bare SQL identifiers. User infix
functions have % stripped.
sql_expr(x, con = sql_current_con()) sql_call2(.fn, ..., con = sql_current_con())
x |
A quasiquoted expression |
con |
Connection to use for escaping. Will be set automatically when called from a function translation. |
.fn |
Function name (as string, call, or symbol) |
... |
Arguments to function |
Using sql_expr() in package will require use of globalVariables()
to avoid R CMD check NOTES. This is a small amount of additional pain,
which I think is worthwhile because it leads to more readable translation
code.
con <- simulate_dbi() # not necessary when writing translations
sql_expr(f(x + 1), con = con)
sql_expr(f("x", "y"), con = con)
sql_expr(f(x, y), con = con)
x <- ident("x")
sql_expr(f(!!x, y), con = con)
sql_expr(cast("x" %as% DECIMAL), con = con)
sql_expr(round(x) %::% numeric, con = con)
sql_call2("+", quote(x), 1, con = con)
sql_call2("+", "x", 1, con = con)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.