read_table: Read an Entire Table

In patelm9/pg13: pg13 Package

Description

Shortcut for a SELECT * SQL statement.

Usage

read_table(
  conn,
  conn_fun,
  schema,
  table,
  verbose = TRUE,
  render_sql = TRUE,
  warn_no_rows = TRUE,
  render_only = FALSE,
  log_file = "",
  append_log = TRUE,
  sep_log = "\n"
)

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

Other table functions: appendTable(), append_table(), create_table_from_df(), create_table(), drop_all_staging_tables(), drop_table_batch(), drop_table(), searchTable(), search_table(), write_staging_table(), write_table()

Other read functions: read_view()

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")
create_test_schema(conn = conn)

# 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]))

# 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]))


# 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)

# Append a table
append_table(conn = conn,
             schema = "test_schema",
             table = "test_table",
             data = data.frame(A = 1:3, B = letters[1:3]))

# 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)))

# 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)

# Message is returned if incoming data contains more than 0 rows
test_data <- read_table(conn = conn,
                           schema = "test_schema",
                           table = "test_table")

test_data

# 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)
test_data <- read_table(conn = conn,
                        schema = "test_schema",
                        table = "test_table4")
test_data

search_table(conn = conn,
             schema = "test_schema",
             table = "test_table",
             values = 1:3)

search_table(conn = conn,
             schema = "test_schema",
             table = "test_table",
             values = "a")

search_table(conn = conn,
             schema = "test_schema",
             table = "test_table",
             values = c("A", "b", "C"),
             case_insensitive = FALSE)

drop_table(conn = conn,
           schema = "test_schema",
           table = "test_table",
           if_exists = FALSE)

drop_table(conn = conn,
           schema = "test_schema",
           table = "test_table2",
           if_exists = FALSE)

drop_schema(conn = conn,
            schema = "test_schema",
            cascade = TRUE)

dc(conn = conn)

patelm9/pg13 documentation built on Dec. 26, 2021, 8:17 p.m.