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Trinh Tong 5 years ago
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3addeb15df
1 changed files with 14 additions and 1 deletions
  1. 14
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      pokemon_sql/pokepart3.sql

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pokemon_sql/pokepart3.sql View File

@@ -16,16 +16,25 @@ WHERE p.name = 'Rufflet';
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 # What are the names of the pokemon that belong to the trainer with trainerID 303?
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-#concat inner join
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+# concat inner join one to many
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+# Select is the outcome
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 SELECT t.trainername as "Trainer", group_concat(p.name) as "Pokemons"
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+# the names from pokemon.pokemons
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 FROM pokemon.pokemons p
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+    # we join to the pokemon_trainer table (so the pokmons have names with their ids
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   join pokemon.pokemon_trainer pt
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   on pt.pokemon_id = p.id
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+    # Then we do the same for the trainers, to match their names to IDs
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 JOIN pokemon.trainers t
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 on pt.trainerID = t.trainerID
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+# on this specific trainer
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 WHERE t.trainerID = 303
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+# group by the trainer name
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 group by t.trainername;
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+# pt shows ownership
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+# using trainer and pokemon table to pull the names of the ids on the pt table
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+
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 # How many pokemon have a secondary type Poison
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 SELECT
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 sum(secondary_type = 7) as "Poison Type"
@@ -47,6 +56,10 @@ GROUP BY ty.name;
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 # How many pokemon only belong to one trainer and no other?
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 SELECT count(distinct pt.trainerID)
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 from pokemon.pokemon_trainer pt;