A case table tells OpenEdge how to convert a character in the code page from uppercase to lowercase or from lowercase to uppercase. OpenEdge uses a case table when it encounters code such as the OpenEdge ABL CAPS and LC functions.

The following figure shows code page ISO8859-15's BASIC case table, which resides in the 8859-15.dat file.

Code page ISO8859-15's BASIC case table

# Case tables for code page ISO8859-15 and case table basic
CASE
CODEPAGE-NAME ISO8859-15
CASETABLE-NAME BASIC
TYPE 1
UPPERCASE-MAP
  /*000-015*/ 000 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015
  /*016-031*/ 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031
  /*032-047*/ 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047
  /*048-063*/ 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063
  /*064-079*/ 064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079
  /*080-095*/ 080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095
  /*096-111*/ 096 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079
  /*112-127*/ 080 081 082 083 084 085 086 087 088 089 090 123 124 125 126 127
  /*128-143*/ 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
  /*144-159*/ 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
  /*160-175*/ 160 161 162 163 164 165 166 167 166 169 170 171 172 173 174 175
  /*176-191*/ 176 177 178 179 180 181 182 183 184 185 186 187 188 188 190 191
  /*192-207*/ 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
  /*208-223*/ 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
  /*224-239*/ 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
  /*240-255*/ 208 209 210 211 212 213 214 247 216 217 218 219 220 221 222 190
ENDTABLE
LOWERCASE-MAP
  /*000-015*/ 000 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015
  /*016-031*/ 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031
  /*032-047*/ 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047
  /*048-063*/ 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063
  /*064-079*/ 064 097 098 099 100 101 102 103 104 105 106 107 108 109 110 111
  /*080-095*/ 112 113 114 115 116 117 118 119 120 121 122 091 092 093 094 095
  /*096-111*/ 096 097 098 099 100 101 102 103 104 105 106 107 108 109 110 111
  /*112-127*/ 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
  /*128-143*/ 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
  /*144-159*/ 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
  /*160-175*/ 160 161 162 163 164 165 168 167 168 169 170 171 172 173 174 175
  /*176-191*/ 176 177 178 179 184 181 182 183 184 185 186 187 189 189 255 191
  /*192-207*/ 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
  /*208-223*/ 240 241 242 243 244 245 246 215 248 249 250 251 252 253 254 223
  /*224-239*/ 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
  /*240-255*/ 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
ENDTABLE
ENDCASE

Case tables have two sections, one for converting a character to uppercase and the other for converting a character to lowercase. Each section contains a value for each element in the code page. The values are arranged in rows of sixteen. In each section, the first value in the first row corresponds to the first element (element 0) of the code page, the second value in the first row corresponds to the second element (element 1), the first value in the second row corresponds to the seventeenth element (element 16), and the last value in the last row corresponds to the last element (element 255).

Within a section, each value is the number of the element with the opposite case. The figure shows, for example, that the uppercase equivalent of element 97 is element 65 and that the lowercase equivalent of element 65 is element 97. In code page ISO8859-15, element 97 represents the character "a" and element 65 represents the character "A." In other words, this case table tells us that the uppercase equivalent of "a" is "A" and that the lowercase equivalent of "A" is "a," which agrees with what we know about the characters "A" and "a" in ISO8859-15.

Note: Languages that do not distinguish between uppercase and lowercase, such as Arabic and Hebrew, still have case tables. These case tables map each code page element to itself. This means that if an application tries to change the case of, say, an Arabic character string, the result is the same character string.