A SAS© hash table contains rows (hash entries) and columns (hash variables). Each hash entry must have at least one key column and one data column. Values can be hard-coded or loaded from a SAS© dataset. A hash table resides entirely in memory, which makes its operations fast. Data does not need to be pre-sorted. A hash table is temporary: once the DATA step execution stops, it ceases to exist. However, its content can be saved to a SAS© dataset or an external database. The hash object is dynamically sized. The example uses the DECLARE method to create the hash table, DEFINEKEY to identify the unique key variable (Supplier_ID), and DEFINEDATA to load additional variables (Supplier_Name, Supplier_Address, Country). The FIND method is used to search for matches between the base dataset (product_list) and the hash table.
Data Analysis
Type : CREATION_INTERNE
Examples use generated data (datalines) or SASHELP.
1 Code Block
DATA STEP Data
Explanation :
The SAS code first creates two temporary datasets, 'product_list' and 'supplier', using DATALINES blocks to make the example self-contained. Then, it uses a DATA step to create a new dataset 'supplier_info'. In this DATA step, a hash object 'S' is declared and initialized with data from the 'work.supplier' dataset. 'Supplier_ID' is defined as the hash key, and 'Supplier_Name', 'Supplier_Address', 'Country' are defined as the data to be stored in the hash table. The 'call missing' function is used to initialize these variables and prevent warnings. Next, the program iterates over the 'work.product_list' dataset. For each observation in 'product_list', the 'S.find()' method is called to search for a 'Supplier_ID' match in the hash table. If a match is found (rc=0), the observation is written to the 'supplier_info' dataset, combining information from both sources. Finally, a PROC PRINT is used to display the content of the 'supplier_info' dataset, presenting the products with their complete supplier information.
The SAS code first creates two temporary datasets, 'product_list' and 'supplier', using DATALINES blocks to make the example self-contained. Then, it uses a DATA step to create a new dataset 'supplier_info'. In this DATA step, a hash object 'S' is declared and initialized with data from the 'work.supplier' dataset. 'Supplier_ID' is defined as the hash key, and 'Supplier_Name', 'Supplier_Address', 'Country' are defined as the data to be stored in the hash table. The 'call missing' function is used to initialize these variables and prevent warnings. Next, the program iterates over the 'work.product_list' dataset. For each observation in 'product_list', the 'S.find()' method is called to search for a 'Supplier_ID' match in the hash table. If a match is found (rc=0), the observation is written to the 'supplier_info' dataset, combining information from both sources. Finally, a PROC PRINT is used to display the content of the 'supplier_info' dataset, presenting the products with their complete supplier information.
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| 1 | /* Création du jeu de données product_list */ |
| 2 | DATA work.product_list; |
| 3 | INFILE DATALINES dlm=','; |
| 4 | LENGTH Product_Id $12 Product_Name $50 Supplier_ID 8; |
| 5 | INPUT Product_Id $ Product_Name $ Supplier_ID; |
| 6 | DATALINES; |
| 7 | 240200100101,Grandslam Staff Tour Mhl Golf Gloves,3808 |
| 8 | 210200100017,Sweatshirt Children's O-Neck,3298 |
| 9 | 240400200022,Aftm 95 Vf Long Bg-65 White,1280 |
| 10 | 230100100017,Men's Jacket Rem,50 |
| 11 | 210200300006,Fleece Cuff Pant Kid'S,1303 |
| 12 | 210200500002,Children's Mitten,772 |
| 13 | 210200700016,Strap Pants BBO,798 |
| 14 | 210201000050,Kid Children's T-Shirt,2963 |
| 15 | 210200100009,Kids Sweat Round Neck,Large Logo,3298 |
| 16 | 210201000067,Logo Coord.Children's Sweatshirt,2963 |
| 17 | 220100100019,Fit Racing Cap,1303 |
| 18 | 220100100025,Knit Hat,1303 |
| 19 | 220100300001,Fleece Jacket Compass,772 |
| 20 | 220200200036,Soft Astro Men's Running Shoes,1747 |
| 21 | 230100100015,Men's Jacket Caians,50 |
| 22 | 230100500004,Backpack Flag, 6,5x9 Cm.,316 |
| 23 | 210200500006,Rain Suit, Plain w/backpack Jacket,772 |
| 24 | 230100500006,Collapsible Water Can,316 |
| 25 | 224040020000,Bat 5-Ply,3808 |
| 26 | 220200200035,Soft Alta Plus Women's Indoor Shoes,1747 |
| 27 | 240400200066,Memhis 350,Yellow Medium, 6-pack,1280 |
| 28 | 240200100081,Extreme Distance 90 3-pack,3808 |
| 29 | ; |
| 30 | run; |
| 31 | |
| 32 | /* Création du jeu de données supplier */ |
| 33 | data work.supplier; |
| 34 | infile datalines dlm=','; |
| 35 | length Supplier_ID 8 Supplier_Name $40 Supplier_Address $45 Country $2; |
| 36 | input Supplier_ID Supplier_Name $ Supplier_Address $ Country $; |
| 37 | datalines; |
| 38 | 50,Scandinavian Clothing A/S,Kr. Augusts Gate 13,NO |
| 39 | 316,Prime Sports Ltd,9 Carlisle Place,GB |
| 40 | 755,Top Sports,Jernbanegade 45,DK |
| 41 | 772,AllSeasons Outdoor Clothing,553 Cliffview Dr,US |
| 42 | 798,Sportico,C. Barquillo 1,ES |
| 43 | 1280,British Sports Ltd,85 Station Street,GB |
| 44 | 1303,Eclipse Inc,1218 Carriole Ct,US |
| 45 | 1684,Magnifico Sports,Rua Costa Pinto 2,PT |
| 46 | 1747,Pro Sportswear Inc,2434 Edgebrook Dr,US |
| 47 | 3298,A Team Sports,2687 Julie Ann Ct,US |
| 48 | 3808,Carolina Sports,3860 Grand Ave,US |
| 49 | ; |
| 50 | run; |
| 51 | |
| 52 | data supplier_info; |
| 53 | drop rc; |
| 54 | length Supplier_Name $40 Supplier_Address $ 45 Country $ 2; |
| 55 | if _N_=1 then do; |
| 56 | declare hash S(dataset:'work.supplier'); |
| 57 | S.definekey('Supplier_ID'); |
| 58 | S.definedata('Supplier_Name', |
| 59 | 'Supplier_Address','Country'); |
| 60 | S.definedone(); |
| 61 | call missing(Supplier_Name, |
| 62 | Supplier_Address,Country); |
| 63 | end; |
| 64 | set work.product_list; |
| 65 | rc=S.find(); |
| 66 | run; |
| 67 | |
| 68 | proc print data=supplier_info; |
| 69 | var Product_ID Supplier_ID Supplier_Name |
| 70 | Supplier_Address Country; |
| 71 | title "Product Information"; |
| 72 | RUN; |
| 73 | title; |
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