Description Usage Arguments Value Author(s) See Also Examples
Retrieve column names of a table in a MS Access database
(referenced by 'edb'). Wrapper around RODBC::sqlColumns().
Notice that the method does NOT retrieve the full table to
get its column names (so it should work even if the table is big).
1 2 3 4 5 |
edb |
An object of class 'edb', such as returned by |
tableName |
Single character string. Name of the table to read in 'edb'. |
onlyNames |
Single logical. If TRUE only returns the column names (vector), and if FALSE returns a detailed table as in
|
testFiles |
Single logical. Should the function test for the presence (file.exist()) of the needed files in the folder before trying to fetch information from the database? |
... |
Additional parameters to be passed to dbListFields(). See
|
The function returns a vector of character strings with the
columns / fields of the original MS Access table, or a table with
full details on the columns (see onlyNames
).
Julien MOEYS <Julien.Moeys@mark.slu.se>
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 | library( "easyrodbcaccess" )
# System check. Ingnore this or set 'testODBC' to TRUE
testODBC <- (class(try(odbcDataSources())) != "try-error") & # Check (R)ODBC
(Sys.info()[[ "sysname" ]] == "Windows") & # Only MS Windows
(.Machine$"sizeof.pointer" == 4) # Only 32-bits
### Windows only:
if( testODBC ){
### Make a copy of MS Access example database:
# (a database of soil profile description)
file.copy(
from = system.file( "soils.mdb", package = "easyrodbcaccess" ),
to = "soils.mdb"
)
### Describe the database (NB: this is not a connection)
myDb <- edb( dbType = "RODBC_Access", dbName = "soils.mdb" )
### Use the database:
# List the column names in a table:
edbColnames( edb = myDb, tableName = "WRB_SOIL_GROUP" )
### Clean-up
file.remove( "soils.mdb" )
### Access 2007 ---------------------------------------------
file.copy(
from = system.file( "soils.accdb", package = "easyrodbcaccess" ),
to = "soils.accdb"
)
### Describe the database (NB: this is not a connection)
myDb2 <- edb( dbType = "RODBC_Access", dbName = "soils.accdb",
accessVersion = 2007 )
### Use the database:
# List the column names in a table:
edbColnames( edb = myDb2, tableName = "WRB_SOIL_GROUP" )
### Clean-up
file.remove( "soils.accdb" )
} #
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.