| SQL | Python |
|---|---|
SELECT name FROM titanic_test_data |
titanic_df["name"] |
SELECT * FROM titanic_test_data LIMIT 5 |
titanic_df.head(5) |
SELECT DISTINCT age FROM titanic_test_data |
titanic_df["age"].unique() |
SELECT COUNT(DISTINCT age) FROM titanic_test_data |
len(titanic_df["age"].unique()) |
| SQL | Python |
|---|---|
SELECT * FROM titanic_test_data WHERE pclass = 1 |
titanic_df[titanic_df.pclass == 1] |
SELECT * FROM titanic_test_data WHERE pclass = 1 OR pclass = 2 |
titanic_df[(titanic_df.pclass == 1) | (titanic_df.pclass == 2)] |
SELECT * FROM titanic_test_data WHERE pclass IN (1,2) |
titanic_df[titanic_df.pclass.isin([1,2])] |
SELECT name FROM titanic_test_data WHERE pclass = 1 AND gender = "male" |
titanic_df[(titanic_df.pclass == 1) & (titanic_df.gender == "male")]["name"] |
SELECT name, age FROM titanic_test_data WHERE pclass NOT IN (1,2) |
titanic_df[~titanic_df.pclass.isin([1,2])] [["name","age"]] |
| SQL | Python |
|---|---|
SELECT pclass, gender, COUNT(*) FROM titanic_test_data GROUP BY 1,2 |
titanic_df.groupby(["pclass","gender"]).size() |
SELECT pclass, gender, COUNT(*) FROM titanic_test_data GROUP BY 1,2 ORDER BY 3 DESC |
titanic_df.groupby(["pclass","gender"]) .size().sort_values(ascending=False) |
SELECT name, pclass, gender FROM titanic_test_data ORDER BY 1, 2 DESC |
titanic_df.sort_values(["name","pclass"], ascending=[True,False]) [["name","pclass","gender"]] |
SELECT pclass, gender, SUM(fare) FROM titanic_test_data GROUP BY 1,2 |
titanic_df.groupby(["pclass","gender"]).sum()["fare"] |
| SQL | Python |
|---|---|
SELECT MIN(age) AS min, MAX(age) AS max, AVG(age) AS mean, APPROX_QUANTILES(age, 100)[OFFSET(50)] AS median FROM titanic_test_data |
titanic_df.agg(
{'age': ['min', 'max',
'mean', 'median']})
|
$connectstring = "DSN=Local Elasticsearch;"
$sql = "SELECT * FROM library"
$conn = New-Object System.Data.Odbc.OdbcConnection($connectstring)
$conn.open()
$cmd = New-Object system.Data.Odbc.OdbcCommand($sql,$conn)
$da = New-Object system.Data.Odbc.OdbcDataAdapter($cmd)
$dt = New-Object system.Data.datatable
$null = $da.fill($dt)
$conn.close()
$dt