Zwischenstand

daten-abfragen/select-basic-2.sql

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+select *
+from customers
+where email like '%@gmail.com';
+select *
+from customers
+where email like '%@web.de';
+select *
+from customers
+where email like '%@web.de'
+   or email like '%@gmail.com';
+
+select distinct SUBSTRING_INDEX(email, '@', -1) as domain
+from customers;
+# Nicht im Kurs, aber aus Interesse ausprobiert ---> Selektiert alle verschiedenen E-Mail Domains
+
+select *
+from customers
+where firstname like 'M%';
+select *
+from customers
+where firstname like 'M_____';
+
+select firstname, lastname, age
+from customers
+where age between 20 and 30;
+
+select *
+from customers
+where age not between 20 and 30;
+
+select *
+from customers
+where firstname in ('Gitta', 'Dana', 'Anne');
+
+select count(*)
+from customers
+where age not between 20 and 30; # 160
+
+select count(distinct baby_names.name)
+from baby_names
+where name like 'Alex%'; # 20
+select distinct baby_names.name
+from baby_names
+where name like 'Alex%';
+
+select distinct baby_names.name
+from baby_names
+where name like '%m%';
+select count(distinct baby_names.name)
+from baby_names
+where name like '%m%'; # 1183
+
+select *
+from baby_names
+where year between 1900 and 1999;
+select count(*)
+from baby_names
+where year between 1900 and 1999; # 161668
+select count(*)
+from baby_names
+where year >= 1900
+  and year <= 1999; # 161668
+
+select *
+from baby_names
+where year = 1900
+   or year = 1910
+   or year = 1920
+   or year = 1930
+   or year = 1940
+   or year = 1950
+   or year = 1960
+   or year = 1970
+   or year = 1980
+   or year = 1990;
+select count(*)
+from baby_names
+where year = 1900
+   or year = 1910
+   or year = 1920
+   or year = 1930
+   or year = 1940
+   or year = 1950
+   or year = 1960
+   or year = 1970
+   or year = 1980
+   or year = 1990; # 15307
+select count(*)
+from baby_names
+where year in (1900, 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990); # 15307
+
+select count(*)
+from baby_names
+where year like '19%0'; # 15307
+
+select count(*)
+from baby_names
+where year % 10 = 0
+  and year between 1900 and 1999; # 15307