spark技术分享JdbcDialect
JdbcDialect is the base of JDBC dialects that handle a specific JDBC URL (and handle necessary type-related conversions to properly load a data from a table into a DataFrame).
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package org.apache.spark.sql.jdbc abstract class JdbcDialect extends Serializable { // only required properties (vals and methods) that have no implementation // the others follow def canHandle(url : String): Boolean } |
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getCatalystType Method
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getCatalystType( sqlType: Int, typeName: String, size: Int, md: MetadataBuilder): Option[DataType] |
getCatalystType…FIXME
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Note
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getCatalystType is used when…FIXME
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getJDBCType Method
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getJDBCType(dt: DataType): Option[JdbcType] |
getJDBCType…FIXME
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Note
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getJDBCType is used when…FIXME
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quoteIdentifier Method
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quoteIdentifier(colName: String): String |
quoteIdentifier…FIXME
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Note
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quoteIdentifier is used when…FIXME
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getTableExistsQuery Method
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getTableExistsQuery(table: String): String |
getTableExistsQuery…FIXME
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Note
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getTableExistsQuery is used when…FIXME
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getSchemaQuery Method
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getSchemaQuery(table: String): String |
getSchemaQuery…FIXME
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Note
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getSchemaQuery is used when…FIXME
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getTruncateQuery Method
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getTruncateQuery(table: String): String |
getTruncateQuery…FIXME
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Note
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getTruncateQuery is used when…FIXME
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beforeFetch Method
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beforeFetch(connection: Connection, properties: Map[String, String]): Unit |
beforeFetch…FIXME
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Note
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beforeFetch is used when…FIXME
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escapeSql Internal Method
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escapeSql(value: String): String |
escapeSql…FIXME
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Note
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escapeSql is used when…FIXME
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