Shortcut for a SELECT * SQL statement.

read_table(
  conn,
  conn_fun,
  schema,
  table,
  verbose = TRUE,
  render_sql = TRUE,
  warn_no_rows = TRUE,
  render_only = FALSE,
  ...
)

Arguments

conn

Connection object

schema

The target schema for the operation.

table

Target table for the operation.

verbose

If TRUE, details on the activity are returned in the console, such as when the querying starting and was completed.

render_sql

If TRUE, the SQL statement for the operation is returned in the console.

warn_no_rows

If TRUE, a warning is given that query has returned 0 rows.

See also

Examples

library(pg13) create_test_schema <- function(conn) { if (!schema_exists(conn = conn, schema = "test_schema")) { create_schema(conn = conn, schema = "test_schema") } } conn <- local_connect(dbname = "pg13_test")
#> Error in rJava::.jcall(jdbcDriver, "Ljava/sql/Connection;", "connect", as.character(url), p): org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.
create_test_schema(conn = conn)
#> Error in h(simpleError(msg, call)): error in evaluating the argument 'conn' in selecting a method for function 'dbGetQuery': object 'conn' not found
# Write a table without dropping write_table(conn = conn, schema = "test_schema", table_name = "test_table2", drop_existing = FALSE, data = data.frame(A = 1:3, B = letters[1:3]))
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Write a table with dropping write_table(conn = conn, schema = "test_schema", table_name = "test_table", drop_existing = TRUE, data = data.frame(A = 1:3, B = letters[1:3]))
#> [2021-06-20 15:26:20] Dropping test_schema.test_table...
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Include the name of the dataframe object in the messages test_data <- data.frame(A = 1:3, B = letters[1:3]) write_table(conn = conn, schema = "test_schema", table_name = "test_table3", drop_existing = TRUE, data = test_data)
#> [2021-06-20 15:26:20] Dropping test_schema.test_table3...
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Append a table append_table(conn = conn, schema = "test_schema", table = "test_table", data = data.frame(A = 1:3, B = letters[1:3]))
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Warning is returned if NAs are in the input data append_table(conn = conn, schema = "test_schema", table = "test_table", data = data.frame(A = 1:3, B = rep(NA_character_, 3)))
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Alert is returned if the input data contains 0 rows test_data2 <- data.frame(A = 1, B = 2) test_data2 <- test_data2[-1,] append_table(conn = conn, schema = "test_schema", table = "test_table", data = test_data2)
#> Error in check_conn_status(conn = conn): object 'conn' not found
# Message is returned if incoming data contains more than 0 rows test_data <- read_table(conn = conn, schema = "test_schema", table = "test_table")
#> Error in read_table(conn = conn, schema = "test_schema", table = "test_table"): unused arguments (conn = conn, schema = "test_schema", table = "test_table")
test_data
#> A B #> 1 1 a #> 2 2 b #> 3 3 c
# Alert is returned if incoming data contains 0 rows write_table(conn = conn, schema = "test_schema", table_name = "test_table4", drop_existing = TRUE, data = test_data2)
#> [2021-06-20 15:26:20] Dropping test_schema.test_table4...
#> Error in check_conn_status(conn = conn): object 'conn' not found
test_data <- read_table(conn = conn, schema = "test_schema", table = "test_table4")
#> Error in read_table(conn = conn, schema = "test_schema", table = "test_table4"): unused arguments (conn = conn, schema = "test_schema", table = "test_table4")
test_data
#> A B #> 1 1 a #> 2 2 b #> 3 3 c
search_table(conn = conn, schema = "test_schema", table = "test_table", values = 1:3)
#> Error in search_table(conn = conn, schema = "test_schema", table = "test_table", values = 1:3): could not find function "search_table"
search_table(conn = conn, schema = "test_schema", table = "test_table", values = "a")
#> Error in search_table(conn = conn, schema = "test_schema", table = "test_table", values = "a"): could not find function "search_table"
search_table(conn = conn, schema = "test_schema", table = "test_table", values = c("A", "b", "C"), case_insensitive = FALSE)
#> Error in search_table(conn = conn, schema = "test_schema", table = "test_table", values = c("A", "b", "C"), case_insensitive = FALSE): could not find function "search_table"
drop_table(conn = conn, schema = "test_schema", table = "test_table", if_exists = FALSE)
#> [2021-06-20 15:26:20] Dropping test_schema.test_table...
#> Error in check_conn_status(conn = conn): object 'conn' not found
drop_table(conn = conn, schema = "test_schema", table = "test_table2", if_exists = FALSE)
#> [2021-06-20 15:26:20] Dropping test_schema.test_table2...
#> Error in check_conn_status(conn = conn): object 'conn' not found
drop_schema(conn = conn, schema = "test_schema", cascade = TRUE)
#> Error in check_conn_status(conn = conn): object 'conn' not found
dc(conn = conn)
#> [2021-06-20 15:26:20] Postgres connection was already closed