Skip to content

SHOW TABLES

In Polars, the SHOW TABLES statement is used to list all the tables that have been registered in the current SQLContext. When you register a DataFrame with the SQLContext, you give it a name that can be used to refer to the DataFrame in subsequent SQL statements. The SHOW TABLES statement allows you to see a list of all the registered tables, along with their names.

The syntax for the SHOW TABLES statement in Polars is as follows:

SHOW TABLES

Here's an example of how to use the SHOW TABLES statement in Polars:

register · execute

# Create some DataFrames and register them with the SQLContext
df1 = pl.LazyFrame(
    {
        "name": ["Alice", "Bob", "Charlie", "David"],
        "age": [25, 30, 35, 40],
    }
)
df2 = pl.LazyFrame(
    {
        "name": ["Ellen", "Frank", "Gina", "Henry"],
        "age": [45, 50, 55, 60],
    }
)
ctx = pl.SQLContext(mytable1=df1, mytable2=df2)

tables = ctx.execute("SHOW TABLES", eager=True)

print(tables)

shape: (2, 1)
┌──────────┐
│ name     │
│ ---      │
│ str      │
╞══════════╡
│ mytable1 │
│ mytable2 │
└──────────┘

In this example, we create two DataFrames and register them with the SQLContext using different names. We then execute a SHOW TABLES statement using the execute() method of the SQLContext object, which returns a DataFrame containing a list of all the registered tables and their names. The resulting DataFrame is then printed using the print() function.

Note that the SHOW TABLES statement only lists tables that have been registered with the current SQLContext. If you register a DataFrame with a different SQLContext or in a different Python session, it will not appear in the list of tables returned by SHOW TABLES.