DOC: Fixing EX01 - Added examples (#54164)

Example read_gbq

Author: DeaMariaLeon

ci/code_checks.sh

@@ -92,7 +92,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
  pandas.read_sas \
  pandas.read_spss \
  pandas.read_sql_query \
- pandas.read_gbq \
  pandas.io.stata.StataReader.data_label \
  pandas.io.stata.StataReader.value_labels \
  pandas.io.stata.StataReader.variable_labels \

pandas/io/gbq.py

@@ -162,6 +162,19 @@ def read_gbq(
  --------
  pandas_gbq.read_gbq : This function in the pandas-gbq library.
  DataFrame.to_gbq : Write a DataFrame to Google BigQuery.
+
+ Examples
+ --------
+ Example taken from `Google BigQuery documentation
+ <https://cloud.google.com/bigquery/docs/pandas-gbq-migration>`_
+
+ >>> sql = "SELECT name FROM table_name WHERE state = 'TX' LIMIT 100;"
+ >>> df = pd.read_gbq(sql, dialect="standard") # doctest: +SKIP
+ >>> project_id = "your-project-id" # doctest: +SKIP
+ >>> df = pd.read_gbq(sql,
+ ... project_id=project_id,
+ ... dialect="standard"
+ ... ) # doctest: +SKIP
  """
  pandas_gbq = _try_import()